Monday noon at the Reading Terminal Market you could nab a heritage corn cookie or order your 23-pound free-range Tom for Thanksgiving while listening to Mendelssohn.

Only if you had really good hearing, that is. Amid the din of the market, a string quartet from the Philadelphia Orchestra played for an hour. It was just one of more than two dozen free appearances across the city and suburbs in which musicians of the orchestra, for the third year in a row, organized to thank listeners for their support throughout the year.

"It's a tough place to play," said violinist Paul Roby, "but people do listen, and I'm grateful."

For sure, you don't come for the acoustics. An "adagio non troppo" from one of Mendelssohn's quartets was too soft to cast its spell, but there was definitely a conversation to be appreciated between a "molto allegro" section and the steely staccato of a cheesesteak spatula hitting the grill.

Some shoppers seemed to barely notice there was a string quartet nestled not far from the Original Turkey stand. But about two dozen core listeners gathered, with one man apparently knowing enough about music to turn the page for violist Kirsten Johnson.

"I was surprised – string quartets are so intimate, and this is expansive," said Ginny Beier, an orchestra fan who came over from the Academy House.

Other kinds of ensembles spent the day engaged in hour-long acts of musical place-making – a cello duo at Elixr Coffee off Walnut Street, a percussion group near 23rd and South Streets, a woodwind quintet at the Haddon Township library.

Speaking volume-wise, it seems like the brass trio playing at the Parc restaurant and the string quartet at  Reading Terminal might have considered trading places. But for violinist Elina Kalendarova, the noise of the terminal offered the virtue of being able to play without fear of being under the microscope.

She said of the experience: "It definitely had that quality of being uninhibited."