You're right, M.Ted. I think popular songs had a longer "shelf life" in the past than they do today.

There was a lot more homemade music in the past. If people liked a song, they would buy the sheet music and learn to play it, usually on the piano. Once you've put that much energy into learning a song, you don't abandon it as quickly as people abandon songs today, in favor of something newer.

Arrangements were simpler, and weren't considered an integral part of the song. (Nowadays, LAYLA wouldn't be considered the same song without the guitar riff, unless Eric Clapton rearranged it himself.) It was easier for lots of musicians to "cover" a song—although they probably didn't use the word "cover" because there was less feeling that a song belonged to the person who first recorded it. In the 50s, people like Dinah Shore or Steve Lawrence & Eydie Gorme made their careers by covering other people's songs—if it's even appropriate to call them "other people's songs."

Sometimes an old Broadway show would be revived, causing an old song to revive in popularity. IF YOU KNEW SUSIE, for example, became Eddie Cantor's theme song, and he would sing at least a few lines of it, rather like "bumper music" every time he appeared on The Ed Sullivan Show in the 50s and maybe 60s.

Somewhere along the line, though, it became fashionable to sing only the chorus, not the verse, and so a lot of old popular songs had their verses forgotten. That's why I think it's fun to hear these old recordings with the verses intact.