"Everybody knows all the songs we do. We just do hits," DeCarolis said.
They don't have a set play list as they prefer to see what the crowd likes, and they take requests.
"It's a different night every night. Nothing's ever the same," DeCarolis said.
During the late 1970s and '80s, DeCarolis and Marchetti played in a cover band, Eastern Standard Band. Marchetti played keyboard and DeCarolis played guitar.
In 1990, Marchetti answered an ad for pianists wanted and learned to "duel" or play along with another pianist for a regular gig at Market Street Live, an entertainment complex in downtown Philadelphia.
DeCarolis started playing piano at Market Street Live about a year later. The two played together at other venues and started their own dueling pianos gig in 1999, DeCarolis said.
Their dueling pianos act has been on the road in recent years, but they expect to get a regular gig at Jolly's Rockin' Piano Bar, a dedicated dueling-pianos club in downtown Philly, Marchetti said.
DeCarolis enjoys the opportunities in a dueling-pianos act -- to interact with the audience more and play requests.
"It's an intimate fun party rather than just people sitting there listening at a concert," he said.
If you go ...
WHAT: Dueling Pianos singalong
WHEN: 7 to 10 p.m. Thursday, July 9
WHERE: Municipal Stadium, corner of Cleveland Avenue and Memorial Boulevard, Hagerstown
COST: $15 per person. Six-person VIP tables available for $150 per table. For tickets, call 301-791-6266 or e-mail firstname.lastname@example.org , or go to www.hagerstownsuns.com .
MORE: Gates open at 6 p.m. and close at 11 p.m. Concession stands will be open. VIP table menu includes all-you-can-eat wings, subs and finger foods.
Must be 21 or older to attend. The rain date is in August, date to be determined.
At least 10 gift baskets from local businesses will be raffled off to benefit Potomac Classical Youth Ballet Company.
For more information about the Dueling Pianos, go to www.duelingpianos.com.