Charles Wadsworth’s Chamber Music Series spans the entire histories of Spoleto Festival USA and the other Spoleto Festival of Two Worlds in Italy (going back nearly 50 years). With 20 years at the helm at New York’s Lincoln Center, Wadsworth is friends with just about every notable chamber musician in the known universe. And he brings quite a few of them to Charleston with him every year.

These events happen daily, at 11 a.m. and 1 p.m., throughout the festival. There are 11 programs in all, each offered twice, for a total of 22 individual hour-plus concerts. Being a world-class keyboard artist (piano and harpsichord) as well, Wadsworth performs often on top of introducing each new number to his audience with his inimitable wit and wisdom.

There’s one thing that often puzzles (and irritates) newcomers. You never know what you’re going to hear until you get there. This long-standing Spoleto custom began in Italy with festival founder Gian Carlo Menotti, who reasoned that a well-chosen chamber program needs no advance billing. That way, you can spring the occasional “modern” or very obscure work on your listeners that may have kept them away had they known it was on the menu.

Some of the musicians may not yet be well-known, but they will be. After all, superstars like Yo-Yo Ma and Joshua Bell were among Wadsworth’s early Spoleto protégés. Many of them keep coming back, like (this year) violinist Chee Yun, pianists Anne-Marie McDermott and Stephen Prutsman, violist Hsin-yun Huang, and cellist Alisa Weilerstein. Other returning regulars will include flutist Tara Helen O’Connor, violinist Daniel Phillips, clarinetist Todd Palmer, and, of course, the St. Lawrence String Quartet.

And that may not be all: Wadsworth retires from Spoleto this year, so who knows what other big names from his past may show up to honor him? Geoff Nuttall, founder of the St. Lawrence String Quartet, may be taking over as director of the chamber series. He was introduced to audiences last year as Wadsworth’s assistant, leading to speculation that Wadsworth was preparing to step down and was perhaps grooming Nuttall to be his successor.

When I interviewed him a few weeks back, the programs hadn’t been decided. But he did share some of the choicest items on his “wish-list” that he’ll be pushing for in his final festival.

We can hope to hear any (but not all) of the following: R. Strauss’s Capriccio sextet, Schoenberg’s Transfigured Night, Brahms’ G minor string sextet, the Mozart or Brahms clarinet quintets, the great French string quartets (Debussy or Ravel), either the Shostakovich Cello Sonata or Piano Trio, Tchaikovsky’s Souvenir de Florence, and the Dohnányi Serenade for String Trio. The only piece we’ll get for sure is the searing Schubert Cello Quintet in the final program, another custom that began with Menotti.

As for the Intermezzi, it was cut back from the usual five events to three this year. These hour-plus concerts kick off with a bang, thanks to mega-pianist Andrew von Oeyen, who will offer a recital of extreme contrasts in style and mood. Beginning with the grace and refinement of several gems by Chopin, he’ll move on to Prokofiev’s violent Sonata No. 7; the “Precipitato” will blow you away. He’ll end with The Mill, a dark-toned piece that he composed.

The following affair is a rousing interlude of strong Italian flavors and spirit. Under the baton of Pierre Vallet, members of the fabulous Spoleto Festival Orchestra deliver Rossini’s glittering overture to Barber of Seville, plus Mendelssohn’s perky Italian Symphony. The third event follows Spoleto custom with a juicy vocal recital showcasing the moonlighting lead singers from Louise, this year’s only opera.