Maybe 2 different abilities. How are these?
Leaf Singing (Su): The leaves of a singing tree constantly sing an enchanting song in the upper register. This song floats on the wind, so that all creatures within 1 mile? must make a DC X Will save or become charmed by the tree, moving toward the tree, taking the most direct route available. The victim may avoid obvious hazards, defend himself, and carry on other activities such as speaking, retrieving items from a pack, as long as he generally continues to move toward the tree. This is a sonic, mind-affecting charm effect. The save DC is Charisma-based (and includes a -X racial penalty?). A creature that successfully saves cannot be affected again by the same singing tree's leaf song for 24 hours.
Trunk Singing (Su): When a singing tree notices nearby victims, the trunk can add a bass line to the leaves' chorus. When the trunk sings, all creatures within 300 ft (?) must make a DC X saving throw or be compelled to walk directly into the shade, lie down, and fall asleep. This is a sonic, mind-affecting, sleep, and compulsion effect. The save DC is Charisma-based.