When trying to learn to sight read music, I am confused about some intervals that are represented on a single staff that are too large(even for slightly larger hands than normal) to span with a single hand.
I assume that the other hand is suppose to grab the note, but then why wasn't it simply notated that way in the first place?
I have seen some instances of notes of a line leaping to the other staff for a single note when they could have been better played by the other hand(there was no difficulty in playing them).
So both cases seem to be at odds with each other. In one case, it is clear the interval is far to large to play with a single hand and the other must "help out". In the other case, "they" specifically notate it as to get the the other hand to play a specific note(sometimes a single note which not only breaks the line across a staff for a single moment) which is more easily played if was note was not moved to the opposite staff.
case 1: I'm talking about intervals over a 10th(which I can reach relatively easily in most positions), something like a 12th or more in some circumstances. And the bass usually has a single note that is well within range. The 3 voice texture is not complex so it's not made for technical reasons regarding playability. The only thing I can see it do is reduce ledger lines, usually not much though.
case 2. The intervals tend to be rather easy to play, the music is not complex, etc. The only thing I can see it do is reduce ledger lines... but its usually only a few and shouldn't be a big deal.
If, as we sight read, we are suppose to, on the fly, determine if a note should actually be played by the other hand for a single instance, how to we actually quickly do that? Just to see that it is a "stretch" doesn't seem to be a very good metric(although it might be in the sense that probably 90%+ of music falls within that realm).
But there is a problem with the ledger line answer: There are examples in the score that use much more in normal circumstances so it is not to make it easier to read as far as ledger lines are concerned.