Thiruppavai is a collection of 30 pasurams by Andal.in praise of Lord Venkatachalapathy/Vishnu.unmarried girls pray for a good married life. They fast and sing these songs early in the morning of 30 days of Markazi masam.They get up early in the mroning take bath and go to temple singing these songs.
It is very freshing to light the lamp and sing these songs early in the morning.
http://en.wikipedia.org/wiki/Thiruppavai