Leaning to play the Piano is a good way to exercise all of the processes of attention.
4. A formal test of divided attention is the Paced Auditory Serial Attention Test (PASAT). This test presents a series of pre-recorded numbers at varying time intervals. The listener must add the last number he heard on the tape to the previous number the he (the listener) had said.
If there is one activity that provides exercise for all these focus processes, I believe it is learning to play the piano.
One must definitely have focus, to pick out those small notes from the ground of the lines in a bar of music.
Sustained focus, of course, is a must if one is to practice for any length of time.
More than one teacher has let out, a primordial scream as their student becomes repeatedly distracted by some irrelevant environmental noise, or marking on the practice sheet, or some internal day dream.