MFD does not locate songs ... it is only tied to a style. the style can be a preset, or a saved one in the USER area or on your USB stick.
Once you create a Song arrangement for your choir, you have to SAVE it to a USB stick. Just make a fold on your USB stick, name it something like .. choir music. Save your finish song in there with its name. All the songs in the folder will be in alphabet order.
Regards
Drake