This idea is false -- at least for now. As long as secular songs are included in a school holiday concert's repertoire, Christmas carols may also be sung [source: Gibbs, Jr. and Gibbs III]. But there's much debate over whether singing any sacred choral music in public schools is a violation of the U.S. Constitution's Establishment Clause. The Constitution's First Amendment says "Congress shall make no law respecting an establishment of religion." This "Establishment Clause" is at the heart of many disputes over what people consider freedom of conscience, freedom of speech and freedom of religion [source: Kasparian]. As of now, however, there's been no ruling by the Supreme Court, and no Constitutional amendments, banning this practice. Some individual school districts, however, have banned Christmas music in school concerts [source: Rundquist].