As of yet I have been unable to add songs not called out in any way to a hard drive image. That said though, if a song is not on the drive image but is present on MIDI disc in the CD changer AND the disc is called for in the hard drive image, songs can be added and may not require the disc at a later point. By playing the song selection, data will be loaded from the disc to the hard drive for quicker access in the future. Afterwards, the song will be present on the hard drive and playable without the CD changer connected.