The beauty about recording technology is that whatever gets recorded can at some point potentially be useful to someone, either the artists or audience or historians of music. A case in point is this ongoing effort by the Lithuanian Nobusiness Records' project of putting out recordings by the late, great Sam Rivers.

This recording of a 1981 concert in Florence, Italy (volume 5 of the project) is called Undulation, perhaps in reference to the wave-like flow of musical ideas from Rivers on saxophone, flute and piano, the funky forward-thinking Jerry Byrd on guitar, electric bassist Rael-Wesley Grant and Steve Ellington on drums.

Thirteen tracks attest to this band's inventive and ahead-of-their-time playing, but are also a testament to the archival process and how it can serve to present new music from a not too distant past that is as revelatory of genius and power is as this series of tracks. Moments of high art occur everywhere on this disc, starting with the solo section cadenza twelve minutes in, simply titled "Tenor saxophone solo." The music evolves in a beautifully organic and soulful fashion. The only problematic element in the concept of this 5th volume of the project is the rather prosaic titles of the pieces (e.g, "Drum Solo", "Flute Section 1", etc.). Still, this takes absolutely nothing away from the groove of the music throughout, as the beat gets rather fusion-like funky a-la-Miles Davis' On the Corner period, so the rhythm was in the air, but this isn't Miles; it's Sam Rivers and younger musicians he manages to channel and focus into over an hour of inspired and invigorating music that engages both the earthy self, the intellectual and the soulful in equal measure.

It is a credit to Rivers' judgment that he gives his younger colleagues a lot of room to stretch out and do their own thing in tracks called "Piano section I and II", as an ensemble, and in solo sections for each of the rhythm section members, who have an impressively mature approach and distinct sound.

The young musicians also kick their venerable leader into some interesting territory of their own in the last third of the disc, which is dominated by flute and rhythm section jamming of a very funky, soulful, gritty nature that ends with some vocalizing by Rivers as he introduces the band that sounds like a mix of scatting and hip-hop before it ever was a thing.