Mingus is a bass player! Mingus thinks like a bass player! Although he can clearly play the piano and uses it for composition, he has only recorded once on piano (Mingus Oh Yeah).
I have had this album for a year and find it intriguing to listen to. It is totally captivating, but lacks the fluency of a trained pianist. The album is full of hesitant moments as Mingus works his way through the improvisations. At one stage he remarks to the sound engineers that "This isn't as easy as playing at home".
Other reviewers have suggested that this is an album for devotees of Mingus and this might be the case. Someone new to Mingus, or jazz, might think that this is an amateur at work, but it is far more than that. It is a master musician struggling to express himself in a strange and uncomfortable environment. It isn't someone "fiddling around", it is someone who knows where he wants to go, but is treading carefully and cautiously in this strange landscape. I think it shows a master carefully processing ways of producing a masterpiece.
Recordings by Jimmy Yancey (e.g. At The Window) are much the same. The hesitation comes not from incompetence but from too much thought!
Certainly an album for Mingus fans. Allmusic awarded the album 4 stars upon its release. Meanies!