Where is my music ?

Where did the music and photos come from ? Does the music show in the Purchased tab in the iTunes Store app for redownloading : About backups in iCloud and iTunes - Apple Support

iCloud backups include nearly all data and settings stored on your device. iCloud backups don't include:

...

iTunes in the Cloud and App Store content (If it's still available in the iTunes, App, or iBooks Store, you can tap to re-download your already purchased content.)

Music copied from CDs, bought from other sites, or no longer in your country's store (or bought from a different country's store ; or if you've hidden it from the cloud : Hide and unhide purchases in iTunes or iBooks on your Mac or PC - Apple Support) won't show, you will have to sync (or unhide hidden purchases) that from your computer's iTunes library (assuming that you have it there).

Photos that were synced to the Air 2 from a computer are also not included in a backup

Not sure what you mean by 'auto-save'.

None of your own music is stored in a backup, neither iCloud nor iTunes - an iCloud restore will download the purchases that it can (or you can redownload them if they are still available), a computer's iTunes restore will copy back content (music, apps etc) from that iTunes library (the actual backup contains your documents, photos taken with the iPad, settings etc)