The musical was scheduled to open on 30 April 1981, with previews starting on 22 April. Shortly before tickets went on sale in mid-February, Nunn revealed to the alarmed producers that he was struggling to write the script for the musical. Despite still having no established book or score, rehearsals began on 9 March 1981 in a church hall in Chiswick, London. The original music director, Chris Walker, became so frustrated with the unfinished score that he quit by lunchtime and was replaced by the film conductor Harry Rabinowitz. The situation improved later that day when Lloyd Webber, Mackintosh and Nunn met with Richard Stilgoe, a musician known for his ability to improvise lyrics on the spot, in hopes that Stilgoe could write an opening song for the musical. By the next evening, Stilgoe had produced a draft for "Jellicle Songs for Jellicle Cats". However, "Memory", an 11 o'clock number for Grizabella that Nunn insisted the show needed as its "emotional centre", still had no lyrics at this point. Lloyd Webber's former writing partner Tim Rice was brought in to write a lyric for the song, but his version was rejected by Nunn for being too depressing. The lyrics for "Memory" were not completed by Nunn until well into the previews.