Many a Singer/Songwriter made a mark in the early 70’s, though few were as unique as Melanie. Her music (even when protest singing) had such a gentle quality that made audiences fall in love with her. Her biggest issue was her close association with the Flower Power Woodstock era, and when times changed, America did not look at her as someone capable of changing with them. Though she had considerable success for a time, she may not have had enough of an impact to crack the Hall.
If Whitesnake were to get in to the Rock and Roll Hall of Fame, would Tawny Kitaen get in too for her work on those videos? Train wreck aside, the music of Whitesnake was very successful and was among some of the better Hard Rock based Pop Metal efforts of the 80’s. Though it is not loved by all, many talented and respected musicians (David Coverdale and Steve Vai for example) were past members of Whitesnake and an induction to honor some of those people while unlikely, is not impossible.
Depending on whom you ask in the Heavy Metal world, Venom was either one of the most important Heavy Metal bands or they were a complete non-factor. Venom is considered one of the first Extreme Heavy Metal bands of note, and although their record sales were dismal (as were many others on this list) their development toward Black Metal, Death Metal and Thrash is often cited as influential.
Sporting a brilliant career as a session musician in the 60’s (He actually may have a shot to get in as a side man), Campbell broke out on his own and produced some of the catchier Pop Country songs of all time and at the start of the 70’s he was a major star. Campbell is already in the Country Hall of Fame, and the question here is does he have enough Rock credibility form his solo work to breakthrough to Cleveland.