Hello LilyRose86,
Thank you for using Apple Support Communities! I understand that there's pause before certain songs play on your iPhone. Thanks for already checking if the same songs play as expected on other devices as well, and I would be happy to help take a closer look at this with you.
If the songs were added using either an iTunes Match or Apple Music subscription, I'd like to have you try the following, testing if you can replicate the issue after each step:
- If streaming the content over cellular data, test when the iPhone is connected to Wi-Fi.
- Download some of the songs in question to the iPhone if they have not yet been downloaded: Add and download music from Apple Music or buy music from the iTunes Store - Apple Support
- If they've already been downloaded to the iPhone, remove the downloads and download them again: Delete music, movies, and TV shows from your device - Apple Support
If you synced the songs to the iPhone from a computer, let's go ahead and remove the songs, then sync them again:
Sync your iPhone, iPad, or iPod using your computer - Apple Support
Keep us posted on the results.
Cheers!