The dismissal of longtime Iron Maiden drummer Doug Sampson in December 1979 may seem like just another minor case of musical chairs so often played by unsigned bands. Die-hard fans of this British heavy metal franchise know otherwise.

Since starting on Christmas Day 1975, the fledgling Iron Maiden had already cycled through three lead singers, just as many drummers, a half-dozen guitarists and even briefly integrated a keyboard player into their midst — all orbiting around Steve Harris, the band's founder, driving force, bassist and true star. But Sampson was a little different.

His friendship with Harris dated all the way back to pre-Maiden days and a shared passage through a ragged bunch of East London pub rockers called Smiler, where the teenagers cut some important musical teeth together. In 1977, when Harris was struggling to maintain a stable Iron Maiden lineup, Sampson was who he called to help shore up the rhythm section.

Now fronted by singer Paul Di’Anno and bolstered by lead guitarist Dave Murray’s talents, Iron Maiden began gathering serious momentum over the next year and a half. This period witnessed the first signs of an emerging New Wave of British Heavy Metal for which ground zero became DJ Neal Kaye’s weekly Bandwagon Heavy Metal Soundhouse.

Listen to Doug Sampson on Iron Maiden's 'Burning Ambition'

Iron Maiden paid tribute to Kaye’s show with the title of their first demo. Recorded on New Year’s Eve 1978, The Soundhouse Tapes was released in a limited run of 5,000 copies on Nov. 9, 1979. Now, with their signing to EMI a foregone conclusion, Iron Maiden’s workload began to accelerate at a head-spinning pace – and that ultimately led to Sampson’s undoing.

As sessions began for Iron Maiden’s self-titled debut, Harris became increasingly concerned as ill health began affecting the drummer. This didn't bode well for a grueling tour schedule that was already coming together for the year to follow.

By his own admission, Harris endured a few sleepless nights over the matter. Then he made the difficult business decision of removing his old friend from Iron Maiden, officially replacing Sampson only four days later with new drummer Clive Burr. Sampson has admitted he was heartbroken at the time, but also somewhat relieved as he too had grown unsure about his ability to cope with the hardships that lay ahead.

In addition to The Soundhouse Tapes, Sampson's brief but important tenure would ultimately be represented by recorded versions of "Sanctuary" and "Wrathchild" found on 1980’s Metal for Muthas compilation, as well as the early-days favorite "Burning Ambition" – which became the B-side of Iron Maiden’s first single, "Running Free."

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