Beyonce to Perform at MJ Tribute Concert ... Via Satellite

Beyonce just joined the growing list of A-listers performing at the upcoming MJ Tribute Concert in Wales -- but unlike the rest of the line-up ... she'll only be a glimmer of her former self.

Promoters behind the "Michael Forever Tribute" in October just posted the announcement to their Facebook page -- Bey will perform one of her favorite Jackson 5 songs ... via satellite.