list of phish halloween surprise musical costumes:
Hallowen '94 - Beatles White Album
On Halloween 1994, Phish performed The Beatles' White Album. The band played every song on the double album except "Good Night", which was played over the P.A. at the end of the set ("Birthday" was covered as an instrumental, during which Fishman presented a birthday cake to Brad Sands, the band's road manager).
Before the band took the stage for their second set, the sound technician began playing "Speak to Me" over the PA, leading the audience to believe the band was about to play Pink Floyd's The Dark Side of the Moon. However, just at the moment "Breathe" would have begun, the recording immediately cut to a sample of Ed Sullivan introducing The Beatles from their famous February 9, 1964 appearance on his show. The band promptly leap into "Back in the U.S.S.R."
Halloween '95 - The Who's Quadrophenia
Later in the night during the band's third set, "You Enjoy Myself" was performed for over forty minutes. The band ended the night with "My Generation", a song made famous by The Who but not included on their Quadrophenia album. The band destroyed their instruments at the end of the encore, just as The Who did decades before.
Halloween '96 - Talking Heads, Remain in Light (!)
For their third musical costume, Phish's rendition of the Talking Heads' Remain in Light lasted 62 minutes and 16 seconds (compared to the Talking Heads's original, at under 45 minutes; elsewhere reported as 54:12), and featured a horn section and Santana percussionist Karl Perazzo.
Halloween '98 - The Velvet Underground's Loaded.
On the second night of a two-night run in Las Vegas, including the previous night's celebration of the band's fifteenth anniversary, the band performed The Velvet Underground's Loaded.
Surprise costume Nov '98 - Pink Floyd's Dark Side of the Moon
Fans in West Valley, Utah were treated to a surprise performance of Pink Floyd's The Dark Side of the Moon sandwiched between the banter of "Harpua" on November 2, 1998
It is widely believed that the impetus for Phish to cover Dark Side two days after the Vegas Halloween show was that the Utah venue was relatively empty with thousands of unsold tickets while just two days prior in the neighboring state, the venue was filled to the brim with many attendees having paid well above face value and spillover fans without tickets remaining outside.
Halloween '09 - after a 5-6 year hiatus from touring/playing, Rolling Stones' Exile on Main Street
On October 31, the only album cover that did not have an axe or a knife through it in the gallery on the website was Exile on Main St., which the band played in its entirety later that night.
Halloween '10 - Little Feat's Waiting for Columbus
On Halloween night 2010, Phish chose Little Feat's 1978 live album Waiting for Columbus.
also for your interest, here's phish surprising fans to Jay Z in Brooklyn in '04. Listen to Jay Z absolutely shocked and amazed by the intensity and noise and appreciation of the phish fans.
https://www.youtube.com/watch?v=om2EQ7YXork
"you guys was hiding all this. you guys was hiding all this from me."