Sorry for the late reply.
You don’t need to mount the drive first. I think in your case here you’d want to enter //192.168.120.10/music but the share name (music) doesn’t have to be the same as the directory name so it’s possibly something else, hopefully that’s enough to get going on. However, you might also fall victim to the cifs version bug. The workaround to that can be found at Smb connection error 112 host is down