On June 8, 1973 ABC TV broadcast the world premiere of the new T.Rex single "The Groover". Warner Brothers took out two full page ads in Billboard Magazine to hype the event, a last desperate gasp for T.Rex to finally make it in America. Although the single was a Top 10 hit in the UK ( the band's last), it did nothing in the US and, to be honest, I can't even find a copy on any of my T.Rex albums.
Sounds to me like T.Rex is imitating its 1971 sound. By '73. Marc Bolan and the gang were doing far more interesting things like "Electric Slim and the Factory Hen".