It is entirely possible to catch two interesting music events on Sunday afternoon in downtown Knoxville.
At 2:30 pm at the Bijou, the Knoxville Symphony Orchestra presents its May Chamber Classics Series concert, and the last one of the season. The program has three major works by Franz Schubert--his "Unfinished" Symphony (Symphony No. 8), the Overture in D, and the Piano Trio No. 2 (Kevin Class, piano; Gabriel Lefkowitz, violin; and Andy Bryenton, cello). Check the KSO link above for tickets, although there may still be tickets available at the box office before the concert.
After the KSO Chamber concert, you'll have plenty of time to stroll the two blocks over to First Presbyterian Church on State Street and catch the Chattanooga Boys Choir in a concert at 5:00 pm. From the church's website:
The Chattanooga Boys Choir (CBC) was founded in 1954 and is the oldest boy choir in the Southeast. The Chattanooga Boys Choir has performed all across the United States and in nineteen different countries around the world including England, Australia, Mexico, and Germany. They have sung for the World Festival of Singing in the Czech Republic, Carnegie Hall, and the renowned Piccolo Spoleto Festival in Charleston, SC. The range of their performances includes the great cathedrals of Europe and the White House to Major League ballparks and the Grand Ole Opry.
The concert is FREE.