A long time ago, like many new librarians, I planned my storytimes around a theme. I would carefully select books, songs, and a craft about monkeys, bath time, zoo animals or whatever other ideas I could find on my shelves or online. The songs changed every week, and I often found myself singing solos. Not fun for me, and definitely not fun for the little ones.
I still think themes are fun, and if you can find enough quality books in your collection go for it. In my current position I don’t have a repeating group for storytime, but when I did I solved the song problem with the Song Bucket.