Honestly I think a good idea would be to say how many times it was played, and then in parenthesis how many of those times were in a particular medley.
For example-
Learning to Live: 450 (100 times as part of Metropolis/Learning to Live/Crimson Sunset and 50 times as part of Schmedley Wilcox)
Now, I would actually prefer that the number be full plays, and then have medleys added on, but you have already said you won't do that, but for example that would look like this-
Learning to Live: 300 (Also played 100 times as part of Metropolis/Learning to Live/Crimson Sunset and 50 times as part of Schmedley Wilcox)