"Tonight At Noon" is an album of leftovers-- half of it is taken from the sessions for "The Clown", half of it from the sessions for "Oh Yeah". Charles Mingus was batting consistently high during this period, and at least one piece from each of these sessions is essential in his catalog ("Tonight At Noon" and "Peggy's Blue Skylight"). The balance of the material is ok, but either a bit uninspired ("Old Blues for Walt's Torin") or lifeless ("Passions of a Woman Loved").
Having stated that, the deluxe edition reissues of "The Clown" and "Oh Yeah" include all this material. I'd recommend skipping this one and going with those. My rating reflects the inconsistency of the material and the lack of reasonable value. Still, if you've got those two records, pick this up for 'Tonight' and 'Peggy', you won't regret it.