By 1977, the Grateful Dead had moved past their infancy phase and into that of a well-established part of the American rock ‘n roll machine that would take over the decade. The band grew from their psychedelic obscurity in the latter half of the 1960s into a powerhouse of musicianship by the time resumed touring in 1976. Come 1977, which many critics and Deadheads consider one of the band’s strongest years, the Dead was a well-oiled machine, picking up new fans wherever they roamed.

Just when many fans thought that the Dead’s songwriting had peaked, the group debuted two of arguably their best compositions in “Terrapin Station” and “Estimated Prophet”. Both tracks would go on to appear on the band’s Terrapin Station album, which arrived in July 1977.

Written by Jerry Garcia and longtime lyricist Robert Hunter, “Terrapin Station” evokes classical poetry with lines like “Inspiration, move me brightly” and “in the shadow of the moon.” “Terrapin” is certainly one of the more renowned works by the Grateful Dead songbook as it takes the listener on an active journey through numerous key and time signature changes on its way toward a climactic finale. That they opened a show with a brand new song says volumes of their confidence in the song’s ability to move us brightly.

As for “Estimated Prophet”, the song penned by Bob Weir and the late John Perry Barlow arrived with its unusual 14/8 time signature with a bouncing groove that’s almost too funky to resist–A “fire wheel burning in the air,” if you will.

Both “Terrapin” and “Estimated” were debuted on this day (February 26th) during the Dead’s performance at the Swing Auditorium in San Bernardino, CA. “Terrapin” opened the show, and “Estimated” made its first-ever appearance just three songs later following a “They Love Each Other” during the opening set.

Relive the live debut of these two Grateful Dead classics from 1977 via the audio player below.

Grateful Dead – Swing Auditorium – 2/26/77

[Audio: Jonathan Aizen]

Setlist: Grateful Dead | Swing Auditorium | San Bernardino, CA | 2/26/77

Set One: Terrapin Station*, Minglewood Blues, They Love Each Other, Estimated Prophet*, Sugaree, Mama Tried, Deal, Playing In The Band > The Wheel > Playing In The Band

Set Two: Samson & Delilah, Tennessee Jed, The Music Never Stopped, Help On The Way-> Slipknot!-> Franklin’s Tower, Promised Land, Eyes Of The World-> Dancin’ In The Streets-> Around & Around

Encore: U.S. Blues

*first time played