In regards to music this is the strangest personal oddity of all, and that because of the number of times it has happened... hundreds? Hell, maybe thousands...
Regarding songs thru the years that I've liked the most.... a HUGE percentage of them I first heard while asleep. I used to sleep with the radio playing every night... these days not as often but I still do so occasionally.
I will hear a song in my sleep, NOT dreaming, an actual song on the radio... and fall in love with it, WHILE ASLEEP!!! I won't know the title of the song or the artist.... and I'll hear it, in my sleep, several times before finally trying to figure out who it is and the name of the song. Sometimes I'm able to do so quickly and other times it can take forever... because it may not be a 'popular' song or something I listen too regularly, (like you mention doing yourself)... due to many reasons, mostly genre. (As you know I like all genres and most do not get much play time on the radio).
Sailing by Christopher Cross, that I mentioned above, was like that for me... and I can tell you exactly when and where I was when I figured it out.... 1980 while in a sleeping bag in a run down old cabin on a ranch we used to hunt on... Point Sal, Calif.
"You Make Me Smile" by Dave Koz... first heard in my sleep... first SEVERAL times in my sleep actually... but this one took me, I think, more than a year to find.
And while I'm at it - one other oddity. And yes, mentioned this before as well. I was in Germany from early 1972 til mid 1973..... and we DID have the Armed Forces Network that played the popular hits of the day but I seldom heard it. In other words.. most of the big 'hits' during that time frame I didn't hear when they came out. TO THIS DAY I'll hear a song thinking it's 'new' only to discover it came out during that time I was in Germany.