A former choir teacher at a Grapevine middle school was sentenced Thursday to seven years in prison for distributing child pornography, the U.S. attorney’s office reported.Daniel Oberlender, 46, pleaded guilty in January to one criminal count. He has been in custody since his arrest on Dec. 20.Oberlender taught music and directed choirs at Cross Timbers Middle School. He resigned a few days after his arrest. Authorities have said the pornography did not appear to involve any students from Grapevine.Federal agents became aware of Oberlender after interviewing a member of a group that advertised sexual content on the Internet, according to a news release from the U.S. attorney’s office. The person said he met people online who were sexually interested in children. That led investigators to Oberlender, who used Skype software to share a video file depicting an adult male engaged in sexual conduct with a young boy, prosecutors said. This includes material from Star-Telegram archives.