Andrew - Gin n Juice is not Phish. That's a track that got mislabeled sometime in the Napster era. I believe that Gin nJuice cover is by a band called The Gourds...
I am a Phish fan, and my concern is these short 15-30 second windows of tunes is not enough to accurately capture what Phish does. I think Harris made some bad choices. Phish plays 3-hour shows for its fans and tours relentlessly. They mix up setlists and have a huge catalog of tunes to pull from. In this setting, certain songs are in there to change the mood, some are there to dance to, some are there to have a laugh, some are to listen to an intricate classically-themed composition, some are there to space out to and some are there to rock out to. Cities is rather unremarkable, however, it's there as kind of a fun song, even a bonding song with fans that go city to city with the band. I would never have chosen it to play for Scott. However, their cover of Lovin' Cup is consistently perfect. They've been doing it for years and it's spot on.
As to why they play covers. They play them because they're fun tunes and it helps to mix up a setlist. To say you've never enjoyed a cover at a concert is absurd. All bands do covers except the unimaginative. I once saw David Byrne cover "I Wanna Dance With Somebody" in a rather straightforward fashion. If he had put it on a studio album the way he played it at the show, it would be pointless because he didn't bring anything new to the table. However, at the show, it was an interesting choice and an entertaining surprise.
How to convert Scott. Here's my thoughts:
First off, Harris, I would stick to studio-recordings only, no live stuff, as Scott seems to be the kind of person who wants to hear a track in its most perfect form, a clean and tight performance. So stick with studio albums, I would say specifically Nectar, Rift and Hoist, with possibly a few tracks from Hoist or a later album. This is the period where their vocals in the studio sound the best. As Harris said, vocals are Phish's major weakness, they totally lack a lead-singer with charisma. But what they lack there, they make up for in composition, musicianship and ingenuity.
Here's my suggestion:
Sample, Julius and DwD from Hoist or Chalkdust Torture from Nectar as pretty straight ahead rock tunes without tongue in cheek lyrics.
Then I would transition into a couple songs that show their versatility and energy: Stash, Poor Heart and The Mango Song.
I believe Rift is the album where they really bring together all their various influences to create a concise sound and album. I would offer up Rift, My Friend and The Horse -> Silent in the Morning.
Lastly, I would play him Split Open and Melt, because that's a sound I've never heard from any other band.
Stay away from Junta, he won't like anything there except YEM, but he would have to sit quietly and listen to the whole thing to judge it, and that's not going to happen in this format. Perhaps you could start the tune, fade out in the middle, listen to the entire thing and then start recording again around the end so Scott hears the whole song. Judging it in these snippets I think is impossible.
So Harris, go studio-recordings only so he can hear every note, use middle of the road lyrics - not silly, absurd or trite ones, and pick songs that are in the 4-7 minute range and are more accessible in general. Don't get into their personality just yet, let him get a hold of what they bring to the table musically.
Scott - Don't judge them based on their singing or lyrics. My view is in most songs, they use the vocals as another instrument, words are chosen for their sound not their meaning in most cases...