how to delete several hundred charts but leave others

I just opened a few jazz playlists to see what songs were there and in the process many hundreds of songs were copied onto my tablet. I have been deleting them one at a time but is there a quicker way? I have about 150 of my own songs that I want to keep. What would be ideal would be an undo function maybe for a later update to ireal. I read through the previous posts and one mentioned dragging songs to the right to delete but I guess that must be for iphone as its not apparently supported on android. Another option might be a checkbox next to each song which enables many to be selected and then deleted.

Thanks for this idea about the checkbox. We will make a note of it and have a think. Yes swiping to the right is iOS only.

Another alternative might be to put the 150 songs into a playlist email it to yourself, Clear your iReal b data (in Android settings>apps>iReal b) then re-import them from the email. (If you are not familiar with emailing playlists, run some tests first to make sure you do not lose your playlist songs.) Unfortunately you will get the exercise songs that come with iReal b, but you can Search for the word 'exercise' and delete them as you are used to doing.
(Android devices can usually only import a playlist with about 300 or less songs, so if you have to do this in the future, make sure you have <300 song playlists.)

Some of the playlists now list the individual songs so if you only need a few, you can just import that ones you want rather than the complete playlist.

Thanks. Emailing the playlist looks like a good option