Definitely Tim. I'm starting to agree with Laurie. Here's what I would do (and Susannah, I hope you're still reading, under an anonymous guise): gradually ween the guy away from these jams. Like, okay, allow yourself to include on this mix a bridge made out of kinda-lame-but-not-outrageously-bad stuff, like "Box of Rain" off American Beauty, or anything off the 1st Moby Grape album. Maybe some Blue Oyster Cult, then throw in some Pink Fairies, some Love, maybe Captain Beefheart. You're not gonna get this guy to come off Phish cold turkey. Best to just slowly ween him away. Also, try the more psyched out, Satanic Majesties era Rolling Stones. Some contemporary indie-jam-potheads like Brightblack Morning Light could work out pretty good too. Let's not forget Polvo, the Rush of indie rock, as that one guy said on the other thread (sorry I forgot your name). Also, Tortoise and the Sea and Cake could maybe have legs with tokin' groovesters.
By the way, y'all know this guy's going to google his band name and find this thread, right?