The frogs are first encountered in Zora's River. If Link uses his Ocarina while standing on the tree stump found in the water about halfway in the region, these frogs will pop up. Playing one of the normal songs, those being "Zelda's Lullaby, "Epona's Song", "Saria's Song", the "Sun's Song", and the "Song of Time" will cause one of them to grow and give Link 50 Rupees as a reward per frog. Also, each song will lead the corresponding frog to grow. Link can also play the "Song of Storms" for them in order to obtain a Piece of Heart.
After they have grown and the Piece of Heart mentioned above has been obtained, Link can conduct the fully-grown frogs. Each frog represents one of the C-buttons or the A-button. When a fly appears above a frog, Link must quickly press the button representing that frog. Once this has been done without fail, completing their song, he will be given a second Piece of Heart.
Link encounters the Fabulous Five Froggish Tenors again on his quest to seal the Portal of Doom. He plays for them the parts of the song he'd learned thus far on that quest; the frogs know the song and teach him the last part that he needs to know, finally enabling him to seal the Portal of Doom.