This is a July 1975 Montreux session, to all intensive purposes its a jam session. Theres only the 4 tracks, and they are all over 10 mins long.
The afterburners are certainly on, and the band is flying from the first number. The band is:
Oscar Peterson - Piano
Milt Jackson - Vibes
Joe Pass - Guitar
Toots Thielmans - Harmonica
Niels Pederson - Bass
Louis Bellson - drums
The unusual element to this is the Harmonica, but as soon as you hear the opening solo on the album you realise that Thielmans is a virtuoso player. He's not playing a diatonic harp but the chromatic, and it sounds great. Goes without saying that the rest of the band swing like crazy and you wont be disappointed by this.
The reason it doesn't get 5 stars is that the sound is a bit dodgy in places (not unlistenable though), but don't let that put you off its well worth getting.