Trying to move apps over to SD Card
Some apps have the ability to store data onto an external SD card.
Just make sure the SD card is formatted first, then check the settings "within" the app itself to see if there's an option to save or move data to the ext SD card.

If I had to guess, I would say Spotify is eating up a lot of your storage memory.
I would start there first and clear out the data from the app via the app manager and then see if the data can be stored on your SD card.