Itunes lost songs

Assuming there are purchases see Hide and unhide music, movies, TV shows, audiobooks, and books - Apple Support and Redownload apps, music, movies, TV shows, and books from the App Store, iTunes Store, and Apple Books - Apple Support. If not is your library being backed up by Time Machine? If so restore the tracks from there.

tt2

Details in the first link I posted. Time Machine is a backup service that comes as part of OS X/macOS. Since you posted in iTunes for Mac I assumed you had a Mac, but perhaps not.

tt2

See Back up your Mac with Time Machine - Apple Support for more details. I suspect if it was enabled you'd know about it, but I could be wrong.

tt2