One thing that Phish fanatics needn't ever worry about is a lack of that quirky preeminent jam band's magical brand of progressive, aggressive pop.

If one of Vermont's finest isn't touring (say, guitarist Trey Anastasio or keyboardist Page McConnell, scheduled to do their solo things at the top of next year), it's Phish bassist Mike Gordon who is out and about, starting this week at Union Transfer, a Philly venue he adores.

"We love it so much, we recorded one of our last live albums there," Gordon said recently of the specifically titled LP June 28, 2015 - Union Transfer, Philadelphia, PA. "That place has got great vibes."

Gordon knows from good vibes. Sidestepping into the recent deaths of heroes such as Leonard Cohen and Leon Russell, he talked about covering each of those artists' songs while in high school bands. "I used to play Russell's 'Jumpin' Jack Flash/Young Blood' medley from his appearance at the 1970 concert for Bangladesh with my first group," he said. "Leonard was one of my mom's favorites. I covered 'Is This What You Wanted' of his during my shows in the past, and Phish, of course, did 'Who by Fire.' " Of course.

The singer-bassist who saves most of his compositions for solo treks such as 2014's Overstep and 2015's The Last Step EP 10, waited until the 21st century to go his own way occasionally, even though he started Phish at the University of Vermont in 1983 with Anastasio and drummer Jon Fishman. "I'm an accumulator, and I like having a lot of different eggs in a lot of different baskets," said Gordon of eventually getting down to solo work, along with directing short films and videos and writing short stories. "It's a juggling act."

As a player who has "always been about integration," Gordon would like his solo stuff to overlap with Phish more - "me be on tour throughout Phish tours maybe, or record while I'm out there.

"Everything I do fills different needs. Phish is about decades of chemistry together with a song repertoire that is set, stylings that are set, and a fan base that is set. I couldn't exist without the other, though: the solo thing, which, for me, always involves uncharted territory. It feels cutting-edge - not avant-garde per se, but a new palette of paints."

Painting anew is what drove Gordon to the doorstep of guitarist Scott Murawski of the dreamy roots-rock ensemble Max Creek. Together, they penned the songs for Overstep during writing retreats in New England and came to a sound that was somewhat familiar to Phish Heads (the loopy reggae of "Yarmouth Road," the weird rhythmic shifts of "Jumping") as well as something open, gauzy, and dear, as with the vocal harmonies and plush arrangements of "Ether."

No matter what he does, Gordon says, "I'd like to keep new fans and old guessing."

8:30 p.m. Monday, Union Transfer, 1026 Spring Garden St. $25, 215-232-2100.