In the mid-1970s, Mark Lewis, then a young keyboard player, struck a deal with a club owner in the San Fernando Valley of California. “We told him our band would play for the door and he could sell drinks on a Monday or Tuesday night when the place is normally empty,” Lewis recalled. “We played a lot of Beatles music back then and so we promoted a Beatles Night.”

The concept spread like wildfire that still burns more than 30 years later in the form of the group, Rain — A Tribute to the Beatles, which will be the star attraction this Friday and Saturday night at Wolf Trap National Park for the Performing Arts.