I dont consider Metalica or AC/DC alternative in any means, but THE X here in Indianapolis bills itself as Indys New Rock Alternative... They have always been heavy on Metalica and they have had Mandatory Metalica for like 15 yrs.... Hey Indy,,, Its 10 O clock,,, Time to Rock.... Then the sound of a dark Bell Gong, but they usually play the deeper album cuts during this time slot. It may not be true alternative, but the audience loves them,, its no different than a station that bills itself as Hip Hop, but plays POP and Dance music as well... Its all in what the stations target music tastes relect, not so much on the format anymore,,, If you ask most people around town what kind of music The X plays, they would simply say Rock, or Hard Rock,,, Kids used to call it Alternative back in the day, but I hardly ever here that term used to describe a Rock band anymore.
As for AC/DC,,,, Definately not alternative, but most the demos will like it.. I think this AC/DC track will cross over to some Mainstream CHR stations as well, Its their big come back, and alot of young teens love AC/DC even though they werent around to hear them when they were new,, same with Pink Floyd, which ive also heard on a station in the Carolinas calling itself the New Rock Alternative,, but this station 93.3 The Planet also plays AOR staple classics about one third of its playlist, and its a dual reporter to Active and Alternative radio.