From The Beatles by Bob Spitz:
Stuart [Sutcliffe] may well have been the natural choice, but his decision to play music perplexed his fellow artists. Bill Harry, for one, remembers the irritation he felt when Stuart flashed the new bass as though exhibiting a finished oil painting. "I said to him, ‘What the bloody hell are you doing?’" Harry recalls. "’You’re passionate about art, not music!’" Stuart shook off such concern with bemused regard. To Harry’s objection, he responded soothingly: "Not, it’s all right. I think it’s art." He had decided to dedicate himself to the band with "as much seriousness and intensity" as he approached painting. "And anyway," Stuart told him, "they’re going to be the greatest. I want to be a part of it."