SOLVED: 1970's One Hit Wonder?

My turn to request help finding a song with minimal cryptic clues...,

I am looking for a soft rock song. I recently heard a brief piece of it over the grocery store Muzak system. The song is very familiar to me but I just can't dig the artist or title out of my memory banks. I remember two distinctive instrumental parts but not any lyrics. I thought it was a one-hit wonder from the 1970's by a group with a name similar to Starland Vocal Band (no, I'm not looking for "Afternoon Delight" or "Moonlight Feels Right"). However, a brute force search of +350 OHW's was a bust.

The first instrumental part is a break between lyrics (dunnn, dun, dunnn, dun, dunnn, dun, dun, dun, dun, dun). The notes sound like they are played on the mid-high end of an xylophone.

The second instrumental part is a 30-45 second guitar solo near the end of the song that repeats the same series of 8 notes but in constantly changing keys. It speeds up until the tempo approaches the speed of the keyboard intro for The Who's, "Baba O'riley". Then the song goes back to the lyrics for about 30 seconds.

Sorry, no easy clues like me humming the tune (besides there are multiple outstanding restraining orders against me singing or humming in public).

Well I had part of it right...
The song is from 1977 but it is not a one hit wonder group.

"Strawberry Letter 23" by The Brothers Johnson

https://www.youtube.com/watch?v=XgsJLGQTfEE