"Opus 17 (Don't You Worry 'bout Me)" is a song composed by Sandy Linzer and Denny Randell and recorded by The Four Seasons in 1966 for their album Working My Way Back to You.

"Opus 17" was the first hit with new full-time bassist and bass vocalist Joe Long.

", "Opus 17" features a rhythmic vocal hook within each verse, but, unlike in most Four Seasons singles up to that point, the song uses very little falsetto from Frankie Valli other than in the closing coda; by 1966, Valli was tiring of singing falsetto and, over the next several years, would begin singing music that did not require it.

"[6] Cash Box described the song as a "pulsating, blues-soaked romancer with an infectious, Seasons-associated repeating, danceable riff.

"[8] The song was released as the official follow-up to "Working My Way Back to You" and reached the #13 position on the Billboard Hot 100 singles chart.