Just a perfect sound and engineered recording; but I find the Dan to be a group that consistently focused on recording quality. From the LP liner notes:
"This is a high fidelity recording. Steely Dan uses a specially constructed 24 channel tape recorder, a "State of the Art" 36 input computerized mixdown console, and some very expensive German microphones. Individual microphone equalization is frowned upon. The sound created by musicians and singers is reproduced as faithfully as possible......"