LOS ANGELES, Jul. 17 – Mary Brunner, one-time member of Charles Manson’s cult, was arraigned yesterday on a second County Grand jury indictment charging her with the 1969 murder of a musician in Topanga Canyon.

Miss Brunner, a 26-year-old librarian from Wisconsin, earlier had been indicted for the July 27 torture-murder of Gary Hinman, but the second indictment, which charges the same offense, superseded the original one.

Superior Court judge George M. Dell, who arraigned the blonde woman, postponed further proceedings in the case until July 22.

The second indictment, which was returned Wednesday, was a technical move on the part of the prosecution after it brought additional testimony before the jury.

Miss Brunner and three others, including Manson, are charged in Hinman’s murder.

Robert Beausoleil 22, another former Manson cult member, was convicted and condemned for Hinman’s murder, and is now on San Quentin’s Death Row.

Miss Brunner was a principal witness against Beausoleil, but she repeatedly has changed her testimony since his trial.

Miss Brunner’s attorney James E. Patterson, on July 22 will seek dismissal of the charge on grounds that the woman was once granted immunity from prosecution.

If the charge is not dismissed. Miss Brunner will enter a plea in the courtroom of Superior Court Judge Kathleen K. Parker.

Meanwhile, selection of alternate jurors continued in another courtroom in the trial of Manson and three other female followers, all charged in the Tate-LaBianca murders.