Though it still stings that The Thing is no more, the 2018 demise of that wondrous trio has left Mats Gustafsson time to pursue many interesting projects: his Fire! Trio and Orchestra; duets with Tony Lugo, Joachim Nordwall, Steve Swell and Liudas Mockūnas; a ninth edition of Hidros; The End; and newest group Cosmic Ear, just to name several. One especially exciting development is the reunion of the AALY Trio, which had started winding down around the same time as The Thing was gaining momentum.

Sustain is the group's first recording in 25 years and also its debut as a discrete unit, with the five previous albums including guest Ken Vandermark (either alone or with his DKV trio). In the intervening decades, Gustafsson has included drummer Kjell Nordeson in his NU Ensemble, Swedish Azz and Fire! Orchestra (though on vibraphone) but has not been documented as working with bassist Peter Janson since the AALY days.

Gustafsson plays his usual baritone, slightly less usual tenor and, most intriguingly flute and harmonica. It is the former that opens the date on "Rock Out" (by the Art Ensemble of Chicago's Roscoe Mitchell, that band from whence the trio took its name) and if the sound is avian, it is more like Alfred Hitchcock's birds. Apart from a nearly 10-minute-take of Frank Wright's title track to his 1967 ESP-Disk LP. Your Prayer, the tunes — four improvisations whose titles are "inspired by the texts of [Swedish author] Sture Dalhström" and pieces by Janson, Vandermark, American trumpeter/The Thing inspiration Norman Howard (from his 1968 recording intended for ESP-Disk) and late New Life Trio bassist David Wertman — are pithy and powerful in their focus.

Anyone familiar with Gustafsson knows his energy can barely be contained and that his brain is swirling with the information gleaned from his tens of thousands of records; that is heard to great effect as he switches between flute and harmonica on the barely three-minute improv "Cover Yourself".

The aforementioned Howard piece, "Soul Brother Genius", which The Thing had covered back in 2001, has Gustafsson on both baritone and tenor — overdubbed? Rahsaan-ified? — and exemplifies the title of the album from where it comes, Burn, Baby, Burn, while Wertman's "Egypt Rock", from the New Life Trio's sole 1978 album, has the percolating groove that The Thing had mastered so well.

The hour-long date closes with a reprise of "Rock Out", almost the same length but just a tad more restrained. The two versions bookend a program full of Fire! and The (next-best) Thing in Gustafsson's long career.