Kadans (Cadence) aka The Moscow Chamber Jazz Ensemble

 

From discogs:

Cadence was a Soviet chamber jazz ensemble, established in 1978 by German Lukyanov. The band had been performing Lukyanov's original compositions and heavily re-arranged jazz standards. Cadence toured around the USSR extensively and participated in a few foreign festivals, including Nord Sea Jazz (1984) in Hague and Jazz Jamboree Festival in Poland. Most musicians played multiple instruments, so the small group of six people had a timbre and expressive variety of a big-band. Lukyanov used complicated rhythmic patterns, unusual arrangement techniques, chromatics, atonality, dodecaphony. Some critics considered Cadence to be one of the most innovative and advanced Soviet jazz bands of the 1970-80s.

Amazing classical fusion.  From the first album which has the title Ivanushka the Fool, track 3:

From the third album track 2 (translated as What a Snowy Spring) presents an astonishingly emotional fugue composition that builds in wonderful intensity a little like our favourite Russian band Arsenal was so able to do: