After a series of side projects and breakups threatened to torpedo one of the only living rock bands still touring with their original line-up 40 years after their first album, Aerosmith has returned, premiering new single “Legendary Child” live on last night’s “American Idol” finale. If it’s not exactly a scorcher, it’s a lot more potent than Aerosmith’s recent track record would suggest, marrying the rough-and-tumble melodic sense of their mid-90’s period with the droning harmonies of early hit […]