[3][4] "Un Poco Loco" is in thirty-two bar form.

[4] It uses the lydian scale, incorporating chords overlapping chords to imply a polytonality (D major 7 over C major 7: CEGBDF#AC#) with the improvisation based on an alternating polytonality and an altered dominant chord.

Particularly remarkable to jazz musicians is the placement of C# against a C major 7 chord; James Weidman attributed this to bitonality, while Tardo Hammer attributed it to an extension of the circle of fifths.

[5] In the late 1980s, literary and cultural critic Harold Bloom included "Un Poco Loco" in his list of the most "sublime" works of twentieth-century American art (from his introduction to Modern Critical Interpretations: Thomas Pynchon's Gravity's Rainbow).

This article about a jazz standard or composition written in the 1950s is a stub.