Please can you clarify for me that in a Tap Formation can have a backdrop that is mounted to a frame? Also is there a restrictive height it must be?

A scenic backdrop that is attached to a frame is permitted, providing that it is not cumbersome (too large or bulky for the dancers to handle easily) and can be taken on by the dancers themselves in no more than 45 seconds and taken off in the same time limit. They must do this in one trip on and one trip off. After they have set the prop they then can take their positions but it all must be done in 45 seconds.

The full rule regarding stage props can be found in the Official Rules Book on page 41.