I had a viscerally negative reaction to this album on first listen. Discord. Chaos. Any time I found myself enjoying it, these intruded. I started writing up a very negative review while listening for a second time, debating whether to give it 1 or 2 stars. At the same time, I started reading up about the background and intentions of the album. About Mingus' life, his anger, his experiences with racism, his illness and death. I found myself appreciating Side 2 (Modes D - F). It still had much of the discord and chaos that was making me uncomfortable, but I could at least appreciate the mastery and composition and the moods it was meant to evoke. I went back to the beginning of the album, closely listening with new ears and started to recognize why this is considered a jazz masterpiece. By the time I returned to Modes D - F, now truly focused on the music, I was blown away. This is a challenging album and clearly isn't background music like so much jazz - it demands attention. It demands struggle. It's worth it and I stand corrected.