'Knock Three Times' was a chart-topping single in 1971 for which of the following?

This song brings back such great memories! I used to love their music.

Twice on the pipes....

Whoa tie a yellow ribbon around the old oak tree if you still love me! ❤️❤️❤️❤️

Rey, we that generation is so lucky and cool man.!

What jolly days those were - everyone sang along to these songs together without any self-consciousness about their own singing skills. Anyone remember all the singalongs on coaches and seaside piers? How sociable things were...

Shouldn’t it have been “Tony Orlando and Dawn” or was that only for tie a yellow ribbon?