where was their first live performance?
UFO Club in London
Pink Floyd
From their earliest days, they employed visual effects to accompany their psychedelic music while performing at venues such as the UFO Club in London. 
who is laughing in dark side of the moon Peter Watts who was he? An English road manager and sound engineer which bands was he a manager for? The Pretty Things and Pink Floyd who are the members of the later band mentioned above? Syd Barrett, Nick Mason, Roger Waters, and Richard Wright, and David Gilmour any well known songs by them? "See Emily Play", "Astronomy Domine" and "Interstellar Overdrive"
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Pink Floyd [SEP] Live performances
Regarded as pioneers of live music performance and renowned for their lavish stage shows, Pink Floyd also set high standards in sound quality, making use of innovative sound effects and quadraphonic speaker systems. From their earliest days, they employed visual effects to accompany their psychedelic music while performing at venues such as the UFO Club in London. Their slide-and-light show was one of the first in British rock, and it helped them become popular among London's underground. To celebrate the launch of the London Free School's magazine "International Times" in 1966, they performed in front of 2,000 people at the opening of the Roundhouse, attended by celebrities including Paul McCartney and Marianne Faithfull.