Pretzel Logic was released in early 1974. A diverse set, it includes the group's most successful single "Rikki Don't Lose That Number" (No. 4) and a note-for-note rendition of Duke Ellington and James "Bubber" Miley's "East St. Louis Toodle-Oo".  During the previous album's tour, the band had added vocalist-percussionist Royce Jones, vocalist-keyboardist Michael McDonald, and session drummer Jeff Porcaro (of Sonny & Cher). Porcaro contributed significantly to Pretzel Logic (as he would on future Steely Dan recordings), reflecting Steely Dan's increasing reliance on session musicians (including Dean Parks and Rick Derringer). Drummer Jeff Porcaro and Katy Lied pianist David Paich would go on to form Toto. Striving for perfection, Becker and Fagen sometimes asked musicians to record as many as forty takes of each track.  Pretzel Logic was the first Steely Dan album to feature Walter Becker on guitar. "Once I met (session musician) Chuck Rainey", he explained, "I felt there really was no need for me to be bringing my bass guitar to the studio anymore".  A rift began growing between Becker-Fagen and Steely Dan's other members (particularly Baxter and Hodder), who wanted to tour. Becker and Fagen disliked constant touring and wanted to concentrate solely on writing and recording. The other members gradually left the band, discouraged by this and by their diminishing roles in the studio. However, Dias remained with the group until 1980's Gaucho and Michael McDonald contributed vocals until the group's twenty-year hiatus after Gaucho. Baxter and McDonald went on to join The Doobie Brothers. Steely Dan's last tour performance was on July 5, 1974, a concert at the Santa Monica Civic Auditorium in California. A recording of the show's opening track, "Bodhisattva", was released as a B-side, and later appeared on the compilation album Gold.  Becker and Fagen recruited a diverse group of session players for Katy Lied (1975), including Porcaro, Paich, and McDonald, as well as guitarist Elliott Randall, jazz saxophonist Phil Woods, saxophonist/bass-guitarist Wilton Felder, percussionist/vibraphonist/keyboardist Victor Feldman, keyboardist (and later producer) Michael Omartian, and guitarist Larry Carlton -- Dias, Becker, and Fagen being Steely Dan's only original members. The album went gold on the strength of "Black Friday" and "Bad Sneakers", but Becker and Fagen were so dissatisfied with the album's sound (compromised by a faulty DBX noise reduction system) that they publicly apologized for it (on the album's back cover) and for years refused to listen to it in its final form. Katy Lied also included "Doctor Wu" and "Chain Lightning".

Answer this question "what was the single?" by extracting the answer from the text above.
"Rikki Don't Lose That Number