Do you know your arpeggios? An arpeggio is the notes of a chord (triad) played one after the other adding an octave above the root to complete, first rising then descending. So if I asked you to play a D major arpeggio would you know what notes to play? Here is an easy way to remember the chord tones which make up the arpeggio.
Because chords are made of three notes placed one above the other in thirds, all you have to do is visualise the stave with the key signature . The chord notes will either be on adjacent lines or spaces. For example place D on the space below the bottom line. The other chord tones will be in the two spaces above the D. The third in the space above the D which is F# and the 5th which is in the space above the F# which is A. Simple. How about a chord of G? The root G sits on the second line of the stave so the notes in the chord will be on the next two lines above the G, being B and D.
Simply visualising the stave with its lines and spaces instantly tells you what the chord notes are. Once you know the chord notes you can play the arpeggio playing the root followed by the 3rd followed by the 5th and finally to the octave above the root to complete the ascending arpeggio.
This is so useful for improvisation and really getting to know your chords.