To this poster’s ears anyway, the music box tune sounds closer to the Swedish Rhapsody[2] than the Luxembourg Polka[3].
I also have to say the music sounds more like Swedish Rhapsody than the Luxemburg Polka to me, however I have kind of a tin ear, and, if legit, you would expect the source to be correct.
So maybe the station carrying the ENIGMA IDs of G2 and E23 has been misnamed all these years and should have been called the Luxemburg Polka station instead. However Swedish Rhapsody sounds better to me

By the way sat_dxer, I have been meaning to ask you about your signature. Yes, I know you have been using it for quite some time, but I assume you are aware that there is no “ENIGMA 2000” transmission classification scheme? The classification scheme you are addressing was originated (I believe, Ary probably has better information) by the original ENIGMA group, not E2K, and was in use by multiple publications / groups long before E2K existed. E2K has only continued the scheme as laid out by ENIGMA. The majority of stations carrying such designations in the ENIGMA Control List (which also existed before E2K did) were assigned by the original ENIGMA group, and only a relative handful have been assigned since ENIGMA stopped publishing and E2K started. And yes, I believe the designators G2 and E23, for the Swedish Rhapsody stations, were assigned by the original ENIGMA group, for sure these IDs for this set of stations had been published before E2K was around (the designator G2 was in use very early on, and E23 was in use by late 1997 or early 1998).
In other words, the ENIGMA Control List is a product of, and originally published by, the original ENIGMA group, not the ENIGMA 2000 group. It was in publication a number of years before ENIGMA shifted focus to other things. ENIGMA 2000 has continued the list, but the majority of the list as it exist today is just as designated by the original ENIGMA group.
T!