The Cyberhymnal 
At Cyberhymnal you can hear Christian hymns in MIDI format while you read the words to the song. The site contains 4,000 Christian hymns and Gospel songs, with the scores, music (in midi format), pictures, lyrics, and background information about that particular song.
You can search for your hymn by name, author/composer, countries, and much, much more. So turn your speakers up and start the sing-a-long.