Theoria, a quartet of four professional vocalists, will return to Pottstown to perform an a cappella concert of beautiful Slavic and other Eastern European Christmas music and Western carols on Sunday, Dec. 18 at 3 PM at St. John the Baptist Byzantine Catholic Church on 301 Cherry Street.

This concert is free and open to the public. A free will offering will be accepted.

Theoria was founded by Andrew Skitko III, of Pottstown, who also directs the ensemble and sings baritone. Skitko performs with the Opera Philadelphia chorus, as well as the Philadelphia Symphonic Choir and The Same Stream Choir, which recently recorded a second album of new choral music.

He is the cantor at the Assumption Byzantine Ruthenian Catholic Church in Trenton, where Theoria frequently performs, and he has served as a cantor at St. John’s church and St. Michael’s Church in Mont Clare.

In addition, Skitko performed in the Pennsylvania Shakespeare Festival production of Les Miserables and appeared as Captain Von Trapp in Pottstown’s Steel River Playhouse’s sold-out 2015 production of The Sound of Music. He also is a private voice instructor.

“We are very excited to return to Pottstown to share this unique music with my hometown community, support Pottstown’s growing arts presence, and again sing in the beautiful setting of St. John’s Church,” Skitko said. “This will be our first Christmas concert in Pottstown. This space is perfect for a performance of this Slavic music, as St. John’s is known in this area for its distinctive ‘onion dome’ roof, stunning stained glass, and traditional iconography.

“Theoria was so well-received during our previous two concerts, both of which occurred in the spring. We were asked to return to Pottstown after both concerts – as many of the audience members said they had never before heard traditional Slavic choral music, and they were impressed by its beauty. Now, we can introduce people to Slavic Christmas music as part of our concert.”

The program will feature Carpatho-Rusyn, Ukrainian, and Russian works of composers such as Leontovych, Tchaikovsky, and Rimsky-Korsakov.

Skitko, a Hill School graduate, earned both his bachelor’s degree in vocal performance and his master’s degree in vocal performance and voice pedagogy from Westminster Choir College in Princeton, N.J.

He will be joined by vocalists and fellow Westminster Choir College graduates Lauren Delfing, alto; Brett Avery-Lawyer, tenor; and Audra Casebier, soprano.

Delfing earned her bachelor’s degree in music education. An original member of Theoria, she is the music and theater arts teacher at First Philadelphia Preparatory Charter School and the associate director of Sister Cities Girlchoir.

Avery-Lawyer, also a founding Theoria member, received his degree in music education. While embracing his lifelong love for classical music, Avery-Lawyer currently works as an agent for Callaway Henderson Sotheby’s International Realty.

Casebier earned her master’s in vocal performance and pedagogy at Westminster after attaining her bachelor’s degree in performance from Kent State University. A semifinalist in the 2013 Classical Singer National Competition, she has performed with Opera North, Opera on The James, the New York Opera Program, and the CoOPERAtive Program at Westminster Choir College.

Convenient, free parking is available in the lot behind the church, which can be accessed via South Street. Handicapped access to the church is available via the South Street entrance.