playlist takes forever to load

I recently converted all my CDs to Apple Lossless. Since I still have a bunch of older songs I don’t care about that are not in Apple Lossless format, I created a smart playlist of just tracks that are Apple Lossless format. It has about 26,000 songs in it. With each iOS and iPhone upgrade, it takes longer and longer for me to play songs in this playlist. A common thing I like to do is call up this playlist and shuffle the songs while listening in the car. But it takes a really long time for the first track to start playing and an even longer time for the music app on my phone to show me which song it’s playing. Once it has loaded, it works fine. But why the lengthy delay? What is it busy doing?