The defendant’s contention that his motion to dismiss the bill of indictment should have been granted for the reason that it con*200tains no attestation by the foreman of the grand jury that twelve or more grand jurors concurred in the finding of a true bill is without merit.
G.S. 15A-644 provides:
“Form and content of indictment, information or presentment.— (a) An indictment must contain:
(1) The name of the Superior Court in which it is filed;
(2) The title of the action;
(3) Criminal charges pleaded as provided in Article 49 of this Chapter, Pleadings and Joinder;
(4) The signature of the solicitor, but its omission is not a fatal defect; and
(5) The signature of the foreman or acting foreman of the grand jury attesting the concurrence of twelve or more grand jurors in the finding of a true bill of indictment.” (Emphasis added.)
G.S. 15A-621 provides:
“Grand jury defined.— A grand jury is a body consisting of not less than 12 nor more than 18 persons, impaneled by a superior court and constituting a part of such court.”
G.S. 15A-623 provides:
“Grand jury proceedings and operation in general.— (a) The finding of an indictment, the return of a presentment, and every other affirmative official action or decision of the grand jury requires the concurrence of at least 12 members of the grand jury.”
In the present case, the indictment bears the signature of the foreman of the grand jury beneath the statement that the bill was found “a true bill” and the witnesses whose names were marked with an “X” were sworn by the foreman and examined by the grand jury. Since the statute requires the concurrence of at least 12 members of the grand jury in order to find an indictment a true bill, the foreman’s signature attesting that the grand jury found the indictment to be a true bill, necessarily attests the concurrence of at least 12 of its members in this finding.
*201Although it is better practice for the foreman’s entry upon the bill of indictment, over his signature, to state expressly that 12 or more grand jurors concurred in such finding, since even a directory provision of a statute should be obeyed, this is not necessary to the validity of the bill of indictment where the foreman’s statement upon the bill is clearly so intended and there is nothing to indicate the contrary.
G.S. 9-27 (now repealed) provided, “The foreman of the Grand Jury shall mark on the bill the names of the witnesses sworn and examined before the jury.” (Emphasis added.) In this connection, the word “shall” is equivalent to the word “must,” which is used in G.S. 15A-644. Nevertheless, in State v. Avant, 202 N.C. 680, 163 S.E. 806 (1932), this Court, speaking through Justice George Con-nor, said, with reference to the contention that an indictment should be quashed for the failure of the foreman of the grand jury so to mark thereon the names of the witnesses examined by the grand jury, the foreman having signed the bill and returned it into court as “a true bill”:
“The foreman of the grand jury is authorized by statute in this State to administer oaths and affirmatives to persons whose names are endorsed on a bill of indictment as witnesses for the State. He is required to mark on the bill the names of such persons as are sworn by him, and examined before the grand jury. C.S., 2336. In S. v. Hollingsworth, 100 N.C. 535, 6 S.E. 417, it is said: ‘The endorsements on the bill form no part of the indictment, and it has been held that the act of 1879 (now C.S. 2336) [subsequently, G.S. 9-27] requiring the foreman of the grand jury, when the oath is administered by him, to mark on the bill the names of the witnesses sworn and examined before the grand jury, is merely directory, and a noncompliance therewith is no ground for quashing the indictment. S. v. Hines, 84 N.C. 810. It constitutes ground neither for a motion to quash, nor in arrest of judgment.’ ”
In State v. Hines, 84 N.C. 810 (1881), speaking through Justice Ashe, this Court said:
“Before the act of 1879 [the former G.S. 9-27] * * * the omission to designate the witnesses who may have been sworn, by a + mark, was not sufficient to quash the bill. The *202fact that they were not sworn must have been established by proof offered by the defendant. * * *
“This principle we think has not been changed by the act of 1879, ch. 12, § 1, which * * * provides that the foreman should mark on the bill the names of the witnesses sworn and examined before the grand jury. We hold that this provision is merely directory, and that it is competent for the state, when the foreman has omitted to mark the witnesses sworn, to show by proof that they were sworn.
“In Massachusetts, they have an act of assembly (Rev. Statutes, ch. 136, § 9), which provides ‘that a list of all witnesses sworn before the grand jury during the term shall be returned to the court under the hand of the foreman; and it has been there held that it is directory merely, and a noncompliance therewith is no ground for quashing an indictment.’ Com. v. Edwards, 4 Gray (Mass.) 1.”
In State v. Avant, supra, the failure of the foreman.to mark the names of the witnesses examined by the grand jury, as directed by the statute, was brought to the attention of the court in time to permit this to be done while the grand jury was still present in the courtroom and this was permitted. However, in State v. Mitchell, 260 N.C. 235, 132 S.E. 2d 481 (1963), speaking through Justice Parker, later Chief Justice, this Court held that the above quoted provision of the old G.S. 9-27 was directory and not mandatory, and the bill of indictment should not be quashed because of such omission, even though it was not brought to the attention of the trial judge in time to permit such correction.
In State v. Calhoon, 18 N.C. 374 (1835), Chief Justice Ruffin, speaking for the Court, said:
“It is the practice for the foreman to sign his name to the finding of the grand jury; and it seems to be a salutary practice, as it tends to the more complete identification of the instrument containing the accusation. We do not know in what it had its origin; but though useful and proper, it does not seem to be essential, nor to have been, at any time, the course in England. * * * It is the grand jury’s returning the bill into Court, and their publicly rendering their verdict on it, in the form ‘a true bill,’ and that being recorded or filed amongst the records of the Court, that makes it effectual.”
*203In State v. Lancaster, 210 N.C. 584, 187 S.E. 802 (1936), the defendant contended that the indictment against him should be quashed, and the judgment pursuant to his conviction be arrested, for the reason that it did not appear by an endorsement of the foreman upon the indictment that any person whose name appeared on the back of the bill as a witness for the State had been sworn and testified before the grand jury. The court held that the motions to quash and in arrest of judgment were properly denied, saying in a Per Curiam opinion:
“The absence of such endorsement was not sufficient to overcome the presumption of the validity of the indictment arising from its return by the grand jury as a ‘true bill.’ * * * The provisions of [the old G.S. 9-27] with respect to the duty of the foreman of the grand jury, are directory, and not mandatory.” 210 N.C. at 585.
In 73 Am. Jur. 2d, Statutes, § 19, it is said: “In determining the mandatory or directory nature of a statute, the importance of the provision involved may be taken into consideration. Generally speaking, those provisions which are a mere matter of form, or which are not material, do not affect any substantial right, and do not relate to the essence of the thing to be done so that compliance is a matter of convenience rather than substance, are considered to be directory.” To the same effect, see: 32 C.J.S., Statutes, §§ 376, 380; 12 Strong, N.C. Index 3d, Statutes, § 5.3.
While, ordinarily, the word “must” and the word “shall,” in a statute, are deemed to indicate a legislative intent to make the provision of the statute mandatory, and a failure to observe it fatal to the validity of the purported action, it is not necessarily so and the legislative intent is to be derived from a consideration of the entire statute. To interpret G.S. 15A-644 as requiring the quashing of a bill of indictment under the circumstances of this case would be to attribute to the Legislature an intent to paramount mere form over substance. This we decline to do.
 The defendant’s next contention is that it was error to deny his request that he, personally, be permitted to question prospective jurors on voir dire, and, subsequently, witnesses at the trial, in addition to questions propounded by his then counsel. There is no merit in this contention.
*204It is well settled that a defendant in a criminal action has a right to represent himself at the trial and cannot be required to accept the services of court-appointed counsel. Faretta v. California, 422 U.S. 806, 95 S.Ct. 2525, 45 L.Ed. 2d 562 (1975); State v. Robinson, 290 N.C. 56, 224 S.E. 2d 174 (1976); State v. Mems, 281 N.C. 658, 190 S.E. 2d 164 (1972); State v. McNeil, 263 N.C. 260, 139 S.E. 2d 667 (1965); State v. Bines, 263 N.C. 48, 138 S.E. 2d 797 (1964). It is, however, equally well settled that “[a] party has the right to appear in propria persona or by counsel, but this right is alternative,” so that “one has no right to appear both by himself and by counsel.” State v. Phillip, 261 N.C. 263, 268, 134 S.E. 2d 386, 391 (1964); New Hanover County v. Sidbury, 225 N.C. 679, 36 S.E. 2d 242 (1945); Abernethy v. Burns, 206 N.C. 370, 173 S.E. 899 (1934). See also, State v. Robinson, supra. Thus, while the defendant elected to retain the services of the court-appointed counsel, the court did not err in holding that the interrogation of prospective jurors and of witnesses must be done through his counsel.
 The defendant’s third contention is that he was entitled to make an opening statement to the jury and the court’s refusal of permission for him to do so was error. There is no merit in this contention.
G.S. 15A-122K4) which provides “each party must be given the oportunity to make a brief opening statement,” does not become effective until 1 July 1978, and, therefore, has no bearing upon the present case. The General Rules of Practice for the Superior and District Courts, promulgated by this Court pursuant to G.S. 7A-34 and published in 276 N.C. 735, relate to procedure in civil actions. Futhermore, Rule 9, thereof, upon which the defendant relies, states: “At any time before the presentation of evidence counsel for each party may make an opening statement setting forth the grounds for his claim or defense.” (Emphasis added.)
The defendant’s request in the present case was not for permission to have his then counsel make an opening statement but for permission to make such statement himself. When his request was denied, his counsel did not request that counsel be allowed to make such statement to the jury. Even if such a request by his counsel should have been granted, the defendant, for the reason *205above stated, while retaining the services of his court-appointed counsel was not entitled to make such statement in propria persona.
The defendant’s fourth contention is that the court erred in refusing to direct the issuance of subpoenas for certain persons whom the defendant said he wished to call as witnesses and in refusing to permit him to call to the witness stand persons then in the courtroom pursuant to subpoenas previously issued.
 We turn to the refusal to issue the requested subpoenas. This request was made after the State rested its case. The court, by inquiries directed to the defendant, ascertained, to its satisfaction, that testimony which the defendant hoped to obtain from these persons would not be material and so declined to issue such subpoenas. In this we find no error.
The Constitution of North Carolina, Article I, § 23, provides:
“In all criminal prosecutions, every person charged with crime has the right * * * to confront the accusers and witnesses with other testimony * *
The Constitution of the United States, in Amendment VI, made applicable to the states by Amendment XIV (Washington v. Texas, 288 U.S. 14, 87 S.Ct. 1920, 18 L.Ed. 2d 1019 (1967)), provides:
“In all criminal prosecutions, the accused shall enjoy the right * * * to have compulsory process for obtaining witnesses in his favor. * *
G.S. 15A-801 provides for the issuance of subpoenas for proposed witnesses in a criminal proceeding and provides that these shall be issued and served in the manner provided in Rule 45 of the Rules of Civil Procedure, G.S. 1A-1, for the issuance and service of subpoenas in civil actions. That rule provides for the issuance of subpoenas by the Clerk of the Superior Court, but also provides for the issuance of subpoenas over the signature of the party or his counsel. It also provides for service of subpoenas by the sheriff “or by any other person not less than 18 years of age, who is not a party.”
*206Thus, the defendant had it within his power to issue, and have served, subpoenas requiring the attendance of the persons in question. It is abundantly clear from the record that whatever ability these people had, to give information pertinent to this prosecution, was known to the defendant long before the trial began. No reason is suggested in the record for the defendant’s failure to subpoena these proposed witnesses prior to the trial, or his failure to advise his then counsel of his desire to have them subpoenaed, if, indeed, he did so fail to advise his counsel.
Furthermore, it does not appear that the testimony which the defendant hoped to elicit from any of these proposed witnesses would have been material in the trial of this action. According to the defendant’s responses to the inquiries of the court, two of them were men whom he suspected of having committed adultery with his wife. Assuming, which seems unlikely, that these men, if called to the witness stand, would acknowledge such conduct, it would not be material to the trial of the present action in view of the fact that it occurred, if at all, ten and eleven years prior to the defendant’s shooting of his wife and after he, with knowledge thereof, condoned the misconduct and he and his wife became reconciled and renewed their marital relations. Another was a minister, not shown to have any knowledge of any circumstance related to the shooting, or of the defendant’s mental or emotional condition, or of his character or reputation.
As we said in State v. Wells, 290 N.C. 485, 491, 226 S.E. 2d 325, 330 (1976), “Here, defendant’s lack of diligence in placing his witnesses under subpoena when he had ample opportunity to do so, thus requiring their attendance from day to day, forestalls his belated attempt to place responsibility on the trial judge for their absence.” Furthermore, as was said in Hoskins v. Wainwright, 440 F. 2d 69, 71 (5th Cir., 1971), “The right to compulsory process is not absolute, and a state may require that a defendant requesting such process at state expense establish some colorable need for the person to be summoned, lest the right be abused by those who would make frivolous requests.” We, therefore, find no ground for disturbing the judgment below by reason of the refusal of the trial judge to issue subpoenas as requested by the defendant.
 A more difficult question is presented by the defendant’s contention that the trial judge refused to permit him to call to the *207witness stand persons who were then in the courtroom pursuant to subpoenas previously issued. In State v. Wells, supra, speaking through Justice Huskins, we said:
“The right of an accused to offer the testimony of witnesses and to compel their attendance by compulsory process, if necessary, is a basic ingredient of the right to present a defense, i.e., the right to present the defendant’s version of the facts, as opposed to the prosecution’s, so the jury may decide where the truth lies.” 290 N.C. at 490-491, 226 S.E. 2d at 329.
Again, in State v. Pike, 273 N.C. 102, 107, 159 S.E. 2d 334, 338 (1968), speaking through Justice Branch, we said:
“It is basic to due process that a defendant in a criminal action be allowed to offer testimony. When the trial judge heard the State’s witness on voir dire, he should have given defendant an opportunity to offer evidence to present his version of the search and seizure or to contradict, amplify, or explain the testimony offered by the State.”
See also, State v. Hunt, 289 N.C. 403, 222 S.E. 2d 234, death sentence vacated, 429 U.S. 809 (1976).
As above recounted in the statement of facts, the defendant testified at length in his own behalf and was permitted to call to the stand other witnesses and present their testimony before the jury. However, certain witnesses, present in the courtroom and under subpoena and proposed to be called by the defendant, were first examined by the court, in the absence of the jury, and, as the result of those examinations, the court concluded that they knew nothing about the circumstances of the shooting, the defendant’s then mental or emotional state or other matters material to the issue before the jury, or that the evidence they would give was so prejudicial to the defendant that it would seriously prejudice his defense to put them on the witness stand. Notwithstanding the court’s original admonition to the defendant that, if the defendant discharged his court-appointed counsel and proceeded to represent himself, the court would not assist the defendant with reference to the rules of evidence, the court refused to allow the defendant to put these proposed witnesses on the stand. Obviously, the court was endeavoring to protect the defendant from disaster due to the defendant’s bad trial tactics.
*208In this, we think the court was clearly in error. It would, of course, have been proper for the court to sustain appropriate objections by the State to specific questions, for the reason that the testimony so proposed to be elicited would be immaterial and irrelevant. The trial court, however, was not authorized to forbid the defendant to offer evidence, otherwise competent, for the reason that, in the judgment of the court, however sound, such evidence would be detrimental to the defendant. The defendant, whether represented by counsel or appearing in propria persona, is entitled to use his own judgment as to the wisdom of introducing otherwise competent evidence. To deny him this right is to deny him his constitutional rights afforded both by the Sixth Amendment to the Constitution of the United States and Article I, § 23, of the Constitution of North Carolina, as above quoted. Washington v. Texas, supra; State v. Wells, supra; State v. Pike, supra.
Nevertheless, not every constitutional error, either State or Federal, is ground for granting a new trial. If it plainly appears from the record that such error “was harmless beyond a reasonable doubt,” the Supreme Court of the United States has said the judgment will not be disturbed on that account. Chapman v. California, 386 U.S. 18, 87 S.Ct. 824, 17 L.Ed. 2d 705 (1967); Fahy v. Connecticut, 375 U.S. 85, 84 S.Ct. 229, 11 L.Ed. 2d 171 (1963). The doctrine of harmless error has repeatedly been applied by this Court, using the same test. State v. Cradle, 281 N.C. 198, 188 S.E. 2d 296 (1972); State v. Taylor, 280 N.C. 273, 185 S.E. 2d 677 (1972); State v. Fletcher and Arnold, 279 N.C. 85, 181 S.E. 2d 405 (1971); State v. Brinson, 277 N.C. 286, 177 S.E. 2d 398 (1970); State v. Turner, 268 N.C. 225, 150 S.E. 2d 406 (1966); State v. Bryant, 236 N.C. 745, 73 S.E. 2d 791 (1953); State v. Bovender, 233 N.C. 683, 65 S.E. 2d 323 (1951). In the Bovender case, speaking through Justice Devin, later Chief Justice, this Court said:
“Verdicts and judgments are not to be lightly set aside, nor for any improper ruling which did not materially and adversely affect the result of the trial. Collins v. Lamb, 215 N.C. 719, 2 S.E. 2d 863. An error cannot be regarded as prejudicial unless there is a reasonable probability that the result would have been different.” 233 N.C. at 690, 65 S.E. 2d at 330.
*209. Our careful review of the disclosures of the defendant’s proposed witnesses in response to the court’s inquiries directed to them, in the absence of the jury, makes it abundantly clear to us that none of these witnesses would have testified to any matter conceivably beneficial to the defendant. The defendant’s own assertions as to what these witnesses could add to his presentation of his defense does nothing whatever to cast doubt upon this conclusion. As Justice Barnhill, later Chief Justice, said in State v. Bryant, supra: “On this record he could have no reasonable hope of acquittal in a future trial, for such a verdict would manifest a clear miscarriage of justice. Hence the verdict and judgment must be sustained.” 236 N.C. at 748, 73 S.E. 2d at 792.
 We, likewise, find no merit whatever in the defendant’s fifth contention, which is that the court should not have permitted him to represent himself since he did not waive in writing his right to counsel. G.S. 7A-457, dealing with waiver of counsel prior to the acceptance of a plea of guilty, has no application to the present case. Here, the defendant, having been appointed counsel for the trial of this case and not contending, either then or now, that such counsel was not competent, exercised his constitutional right (see, Faretta v. California, supra) to represent himself for the remainder of his trial. This was done after the court, upon proper inquiry, ascertained that this was, indeed, the desire of the defendant, notwithstanding the court’s advising him that he would be subject to the same rules of evidence applicable to defendants represented by counsel. Under these circumstances, the court had no choice but to permit the defendant so to proceed, and, in so doing, committed no error.
That the defendant’s court-appointed trial counsel was competent is not only presently unquestioned by the defendant but is affirmatively established by his assignment of error which we next note.
 The defendant’s final contention is that the court below erred in not appointing his court-appointed trial counsel to represent him on this appeal. Normally, it is obviously advisable to appoint a defendant’s trial counsel, with or without other counsel to assist him, for purposes of presenting his appeal and we are not to be understood as suggesting the contrary. However, the *210defendant’s present contention is sufficiently answered by noting that, at the conclusion of his trial, the defendant addressed the trial court as follows:
“I make a motion on mutual agreement between Mr. Finch and myself that another lawyer be appointed to me to make a legal and fair appeal to the North Carolina Supreme Court.”
His court-appointed trial counsel was then present in the court having remained therein, throughout the trial, at the direction of the trial judge in order to be available to the defendant for such legal advice as the defendant might desire.
We find no merit whatever in any of the defendant’s assignments of error brought forward in his brief. Other assignments of error, contained in his statement of the case on appeal, are deemed abandoned. Rule 28 of the Rules of Appellate Procedure, 287 N.C. 679, 741. We have, however, examined these also and find no merit therein.