This is "The Quazy Quintet" from Madhouse. It's a long song (about 7 1/2 minutes), covering the majority of the scene it takes place in. Most of the occurrences of the main theme throughout the song are merely accompaniment to the dialogue, with the exception of the first one and the last two.
Throughout, we get the various patients' moments:
1. Chandra, the rebel
2. Howard, who believes he is incredibly talented at something; he's just not quite sure what it is yet
3. Evelyn, the randomly paranoid
4. Butch, who is out for revenge for his father's supposed murder
5. Steve, who has two sides: a good one and a bad one; this is represented by two actors together on stage