thank you! heres what i understand so far.the bass staff is only played on the first half of the keys (lower pith so bass).the treble staff is played on the 2nd half of the keys (but can it be played on the other half?)each line and space is a key on the piano.now, what are all of the lines that join the notes up. etc. does that mean play them all at once? what do the hollow ones mean?