As classical musician, I hardly ever dealt with music that prompts for open-ended loop, i.e., a segment of music that is supposed to be repeated unspecified number of times until certain cue to stop.
Is there commonly recognized/accepted sign for such a feature?
TIA
Igor Borodin
“Vamp” is used in musical theatre and means to repeat a section until a cue is given to continue…
Thank you for the prompt reply.
Since the segment in question is from an exercise, in other words, the intended audience are not professional musicians, I’m afraid such a specific term may be not familiar to them.
(A confession: it’s not familiar to me neither 
)
But regardless of that, thank you!
Music that is repeated freely against other music until cued or directed in some other way to stop is enclosed in repeat marks and a thick line is drawn out from the right repeat mark (on the middle line of the staff) to show the duration. A written indication such as “repeat ad lib” or “repeat 5 times” etc. can then be then placed above the extension line to be more specific.
However, in your second post, you mention that this an exercise, not a ad lib. passage within an actual piece. In the case of free-standing exercises one can place the remark “repeat ad lib.” above the relevant sections.
Thank you, John, for the suggestion.
IB