Use Playlists. Playlists is your friend!
The design concept of Ballegro is that it's a 'library' holding a huge selection of songs. Ask The Maestro feature allows you to find/search your perfect music for the class. The best Ballegro practice is to play your Playlists in class. You choose and add the wanted songs onto the Playlist in advance. You can re-order all your chosen songs on the Playlist. Then during the class you just playback your playlist which already holds all your pre-chosen songs in the order you want.
Check out our help article Playlist Builder to learn how to build your playlists step by step.