Wahey, a My Little Pony rock group! These ponies came in bright colours, and even had hairbrushes shaped like electric guitars which could be worn around their necks (see pictures). Each pony is shown with her correct brush.
Two versions of Pretty Beat exist, the one below was sold all across the world as far as I can tell, the other (left) was exclusive to North America.
The Rockin' Beats are somewhat special in that they make a television appearance in one of the episodes of My Little Pony Tales as Melody's backing group. They keep their original names and the band name, but bizarrely Tuneful has gone green and lost her horn. Well, happens to the best of us, I suppose!
In the comics too, the Rockin' Beats went from the usual rather magical world of My Little Pony to the world of the My Little Pony Tales with few problems. Tuneful suffered from stagefright in one story, whereas a couple of years earlier she had been wiggling her nose to make the music of insects audible. :) I do remember that Sweet Notes in her original incarnation was supposed to have one of the sweetest voices in ponyland, but by the My Little Pony tales era, she was sidelined to playing guitar, and singing backing vocals. The hardships of the music industry, huh? :)