Hello,
The quickest way to do this in Myriad standard is to use the Myriad Manager to view all the Carts in the song range. Then hold down the <CTRL> key and click on all the Carts in a range that you want to categories into a Song Category. Once you have selected all the 'pop' songs for example, click on the Mass Edit button (looks like a wave form) and select Change Category / Type. You can now select Song and 'Pop' Category. When we do this we tend to do it in smaller blocks to make it easier so maybe start with 200 Carts, classify them then move on to the next 200. To make life easier you could also limit the initial Audio Report to show Carts that do not have Type / Category set. That way you can refresh the search after each operation so that only the remaining unclassified Carts are left.
If you have AutoTrack Pro then you can also use the Mass Changer in ATP or the Song / Link Reorganiser tool.