who is associated with the musical artists from jelly roll morton and fats waller ?
SELECT DISTINCT var_uri where brack_open var_uri dbo_associatedMusicalArtist dbr_Jelly_Roll_Morton sep_dot var_uri dbo_associatedMusicalArtist dbr_Fats_Waller sep_dot var_uri a dbo_MusicalArtist brack_close