“He just blew me away, and I started lobbying to try to get him,” Mr. Salomon said, recalling stalking Mr. Padmore in 2016, when the tenor received the vocalist of the year award from Musical America. “And after five years of bugging him, we finally got him.”

Mr. Padmore said that he had been intrigued by the organization’s goal of making music affordable.

“I was really delighted to hear about it,” Mr. Padmore said in a telephone interview, noting that he also serves as the artistic director of the St. Endellion summer festival in Britain, where artists donate their services to keep costs down. “I think what they do with these concerts is completely admirable.”

From the start, the concerts have drawn discerning audiences. A 1902 review in The New York Times of a program at Cooper Union, the series’ first home, said that the audience’s “attention and manifest understanding are such as to put pretentious up-town audiences to shame.”

The organization still draws engaged, knowledgeable crowds to hear its chamber music and recitals. The pianist Garrick Ohlsson, who has performed several times, said he had found the subscribers “a passionate and well-informed audience — and beautifully behaved.”

In addition to the Town Hall series, Peoples’ Symphony has two six-concert series at Washington Irving, which has general admission seating, and subscriptions cost $50 (or $8.33 a concert). Mr. Salomon said many subscribers arrive early to make sure they can get the best seats, or sit with large groups of friends or relatives. The slightly more expensive Town Hall series has assigned seats. To attract younger listeners, subscribers to any series can now bring up to two children for free, and $25 student passes allow access to all 18 concerts, which would let completists hear them for just $1.39 apiece.