Downloaded score has both Piano and Bass guitar parts when listened to, but I only see the notes for piano on musescore

Wasn't really sure what I was supposed to call the subject so I'm sure you got confused when you first read the title.

I recently downloaded a score for Fly me to the moon and when I hit the play button I can hear both a piano and bass guitar, but on the actual file itself, I can only find the piano sheet music.

Is the bass part hidden somewhere and do I need to do something in the settings to hear it?

Thank you in advance!