When you find a song that you enjoy, add it to your Favorites so that you can easily access it again. You can also create your own song collections in Yousician. With collections, you can group your favorites by E.g. artist, genre, or by exercise type.
How to add to favorites
You can add a song to your favorites by selecting the Favorite 
button. Selecting the same button removes the song as your favorite.
You can find all your favorite songs from the Your favorites collection in the Songs tab. Select Your favorites button to view them.
How to create song collections
To add a song to a collection, select More options 
and then Add to collection. Once done, you can pick an existing collection or create a new one.
When you want to edit your collection, open it from the Your Collections row in the Songs tab. Once open, select More options . You can change the name of the collection, remove songs from it or delete it. If your collection includes lots of songs, use the Filters to find songs you want to play.