Jazz critic
Nat Hentoff interviewed Henderson for the album's original
liner notes essay, and Henderson described the creative impulses behind several of the songs to Hentoff. The title track, "Inner Urge," which has since become a
jazz standard, was a reflection of a time in his life when Henderson was "coping with the anger and frustration that can come of trying to find your way in the maze of New York, and of trying to adjust the pace you have to set in hacking your way in that city in order to just exist." Henderson also told Hentoff that "Isotope" is a tribute to
Thelonious Monk and Monk's use of musical humor. Hentoff writes elsewhere in the liner notes that "El Barrio" represents Henderson's attachment to the "Spanish musical ethos", and that the piece was inspired by Henderson reflecting on his childhood in
Lima, Ohio. Henderson is quoted as saying that he gave the other musicians "two simple chords, B minor and C major 7 (B phrygian)", and asked them "to play something with a Spanish feeling" while he improvised a melody for the piece. ==Reception==