They may belong to an elite group of Sixties survivors, but unlike others of that ilk, Jethro Tull have never attained the special stature accorded others of that ilk. Sure, ‘њAqualung’ќ remains a perennial classic, and the band’s brainy synthesis of styles — prog-rock, jazz, folk, classical and even parcels of medieval melodies — bequeaths them a certain sophistication typical of a time when Rock deliberately strayed outside its borders.

Nonetheless, where other bands of Sixties vintage and sixtysomething birthdays test the limits of diehard devotion ‘“ a fanaticism that allows the Rolling Stones to tip the scales with their concert grosses and motivates 20 million fans to vie for 18,000 tickets to Led Zeppelin’s one-off reunion — Tull’s journeyman consistency makes them seem rather modest indeed.

Still, Ian Anderson and company have managed to create a reliable cottage industry, built on non-stop touring and the ability to repackage their catalogue through a steady stream of live albums and archival offerings, three of them this year alone ‘“ Live at Montreux 2003, The Best of Jethro Tull Acoustic and Ian Anderson Plays the Orchestral Jethro Tull .

And if the enthusiastic crowd that greeted them last night at Hard Rock Live — the next-to-last stop on their 2007 North American jaunt — was any indication, the market for all things Tull has yet to reach the level of over-saturation.