Rock of Ages is what it sounds like, another 80s rock band worshipping rock and roll. If you are looking for something heavy this song (just like all of Def Leppard's discography) will fall short and leave you disappointed. This song is for those metalheads who like a variety of music. Its a rock song, a pop rock song, leave it at that.
The song is pretty generic; pop melodies, tenor ranged singing, lyrics about good ole rock 'n roll amongst other things. The drums are simplistic and easy. The guitar sticks to short little phrases during the verses. The guitar will become a bit more prominent during the chorus but even with the brief guitar solo will fail to achieve anything unique or special, the guitar really is just there to make it a pop rock song instead just a pop song. As already said, the singing is in a tenor range, the lyrics aren't anything special but are packed with 'yeah'. I should mention the bass too, it keeps it simple but catchy. The catchiness of the chorus and the bass are the song's biggest saving throws.
All that being said though, its a fun song, its a catchy song and I like it. Its a shame it wasn't included in the Rock of Ages movie. I must stress again though, if you want something heavy or if your anti-popular music then just avoid this song (and movie of the same name).