In late 1967 Pink Floyd stayed at Alice Cooper's house before appearing on American Bandstand: on both occasions Syd Barrett completely baffled his hosts

In November 1967 Pink Floyd put out their third single, Apples And Oranges. Compared to previous releases See Emily Play and Arnold Layne it was rather slight, although frontman Syd Barrett seemed happy enough.

"It's unlike anything we've ever done before," said Syd. "It's a new sound. Got a lot of guitar in it. It's a happy song, and it's got a touch of Christmas. It's about a girl who I saw just walking around town, in Richmond. The apples and oranges bit is the refrain in the middle."

Promotional duties came a-calling, so Floyd flew to California to begin a US tour and to appear on television. The trip kicked off with a show at Winterland in San Francisco, before they travelled south for two shows at the Cheetah Club in Santa Monica, where Alice Cooper were the de facto house band. The musicians lived together is a house in Venice Beach, and invited Floyd to stay while they were in the area. Syd Barrett, it appears, made quite the impression. During breakfast, he was so high he believed his cornflakes were singing and dancing. And that wasn't all.

"He never talked," guitarist Glenn Buxton told Trouser Press in 1977. "But we’d be sitting at dinner and all of a sudden I’d pick up the sugar and pass it to him, and he’d shake his head like ‘Yeah, thanks.’ It was like I heard him say ‘Pass the sugar.’

"It’s like telepathy, it really was. It was very weird. You would find yourself right in the middle of doing something, as you were passing the sugar or whatever, and you’d think ‘Well, damn, I didn’t hear anybody say anything!’ That was the first time in my life I’d ever met anybody that could actually do that freely. And this guy did it all the time."

Next up, two TV shows, The Pat Boone Show and Dick Clark's American Bandstand, where the band would mime to Apples And Oranges. While footage from the former appears to have been lost, the American Bandstand footage exists, but it's clear that Syd Barrett is beginning to show the signs of the mental deterioration that would result in his departure from the band. He looks vacant, and barely manages to lip-sync his way through the song, before greeting's Clark's softball questions with monosyllabic answers. He was clearly in trouble.

It was the beginning of the end for Syd, and his erratic behaviour increased, making him impossible to manage. He was gone by early 1968.

"We tried to keep Syd going for as long as possible," Roger Waters said. "I really wanted Syd to become what Brian Wilson was in the Beach Boys – for him to stay in the band and keep writing songs, but not to perform with the band. But it wasn't to be. He kind of had other ideas, and so did our manager at the time. But you know, the songwriter is the goose that lays the golden egg. And everybody recognizes that."