I’ve noticed recently that when I listen to new (to me) versions of things I’ve heard many times before – Mozart’s operas, say, or some of Handel’s – I find myself wanting to comment that the tempo sounds slow. In some cases the tempo really is slow, but I think there’s something else going on as well.
You know how when you first study a foreign language, everyone speaking it seems to talk very fast, but then once you become more fluent you can process the incoming information better and speech seems to proceed at a more normal pace? I think something similar happens with music, at least for me, in that once I’m familiar with it, it feels slower because I am no longer absorbing it as well as listening to it. Mentally I have a little more time to notice what is going on – and so the tempo feels slower than it might have in the past.