In my opinon Queen had 100 to 200 unpublished songs performed by Mercury. This ghost songs was produced between 1987-1991 and additional unpublished music track from 70 ties and 80ties . They had video material fom intensiv works during Miracle session, Innuendo session and Made in heaven session. Camera recorded work of Freddie and band in recording studio between 1987 to/and 1991