"Pretty Little Baby" wasn’t supposed to be a Marvin Gaye song. As Gaye, writer-producer Clarence Paul and session musician Dave Hamilton laid down the song’s backing track for Stevie Wonder, Gaye decided to keep the tune for himself.

Instead of recording the Christmas-themed "Purple Snowflakes" for Wonder in Motown’s Detroit studios, Gaye took a liking to what he and his band-mates were putting together and wrote lyrics of his own to go with the music. Gaye’s spark of inspiration would eventually land him at number 16 on the US Billboard R&B charts.

"Pretty Little Baby," a single released by Tamla Records on June 18, 1965 and never included on a Marvin Gaye LP, is a bit of an anomaly in the trajectory of Gaye’s career. The Prince of Motown comes in a few different flavors: candle-lit, bedroom love-funk (see "Sexual Healing"); straightforward, feel-good Rhythm and Blues (the undeniable "How Sweet It Is (To Be Loved By You)"); and thoughtful, intricately produced masterpieces ("Mercy Mercy Me (The Ecology)"), to name a few. But “Pretty Little Baby” doesn’t fit into any of those categories.

The somewhat melancholy song, marked by a twinkling piano riff, fuzzy rhythm guitar and a pleading, soulful vocal performance, strayed from what Gaye was putting out in 1965. Just four months earlier, Gaye had released the single "I'll Be Doggone," a driving, upbeat number that topped the R&B charts and made it into the top ten for Pop. "Pretty Little Baby," a decidedly un-funky, haunting song that largely hovers in the minor key, was a leap in the opposite direction.

But the new single was only a short-lived stylistic detour for Gaye. Three months after "Pretty Little Baby" came out, Gaye released his next single, "Ain't That Peculiar," another cheerful song in the vein of “Doggone” that, once again, came in at number one on Billboard’s “Hot R&B Singles” charts and snagged a spot in the top ten for Pop.

Gaye wound up singing and recording "Purple Snowflakes" in 1964 just before "Pretty Little Baby," though the Christmas jingle wasn’t released for a few decades. Listening to the songs side-by-side, you can’t help but wonder what it would be like to hear Stevie Wonder wail over the backing track. The fact that I can’t stop playing "Pretty Little Baby" on repeat probably means things worked out for the best.