Looks like the cover of "Basically Frightened" by Colonel Bruce Hampton was in tribute to him, as he died the day before on May 1st, 2017. Nice little gesture from Trey. Col. Bruce Hampton and members of Aquarium Rescue Unit shared the stage with Phish a number of times between 1991 and 1994 and the two acts were part of the inaugural H.O.R.D.E. Tour in 1992.

Reading an article from Jambase about this show and they talk about Trey's other tributes to the "Tulsa Sound".

> Later in the first set, the Trey Anastasio Band tipped their hat towards one of the artists most closely associated with the Tulsa Sound – Leon Russell. TAB served up a debut cover of Russell’s “Delta Lady.” ... There was another tribute to the Tulsa Sound ahead in the encore slot. In the middle of Anastasio’s solo on "Push On 'Til The Day", the guitarist led his mates through an unplanned detour to J.J. Cale’s “Call Me The Breeze.” After the band returned to “Push,” they jammed on another of Cale’s originals – “Cocaine” – and eventually finished “Push On ‘Til The Day.”