I would like to be able to play 8ths (2 same-note chords) fast and without stumbling on the adjacent notes. I think it can add color to some basic songs. Question is: what's a good way of practicing them in the piano? Just play a scale using it instead of the single note?
Playing 8ths (AKA Octaves)
Creds: I've been a piano teacher of all levels for more than 10 years.
If you're just beginning, start off learning 6ths first. 6ths use the exact same arm motion as 8ths, except 8ths are wider, and cause more arm strain. Thus, it's best to learn 6ths before 8ths to get the hang of it. (depending on how big or small your reach is.)
What you need to be able to play good 6ths or 8ths:
- Be able to hold the position of a 6th or 8th. You need to know the distance required and call on it automatically. To do this just play a 6th or 8th, close your eyes and memorize how it feels to play that interval. How does your hand feel? How far apart is it? Then take your hand away from the piano, shake it out, and then set your hand on your lap and stretch your 1 and 5 out to where you think they need to be to hit the 6th or 8th. Now, put it back on the piano and see if it fits. If your hand lands on the 6th or 8th cleanly, great, if not try again until successful. Keep doing this until you've successfully got the 6th and 8th at least 10 times in a row without any mistakes.
- Arm motion of arm/hand/finger unit: move from one key to the next accurately. This skill is called by both 6ths and 8ths, so learning 6ths arm motion will also transfer to your 8ths. Basically the idea is to pick up your hand and move it to the next desired key. You'll want to keep your hand relaxed while you move and play. (Learning to relax takes at least a month or two of dedicated practice time) Keep your motions as small as possible. The smaller you move, the shorter your distances, the better. You'll want to direct your motion sideways and not up and down. When you play C to D, think of skipping a rock across water, stay to the surface and move sideways.
A good exercise to understand the arm motions is: Take an invisible salt shaker in your hand, and do small shakes as gentle and fast as you can while you glide your hand left-right across a table, while keeping the distance above the table at about 2-3 inches. The salt shake motion is like hitting the 6ths or 8ths, and the glide is moving from one key to the next while your arm moves.
Starting on D's (8ths) play each key listed 3-8 times: D D D, D# D# D#, D D D, Db Db Db, D D D, (loop)
Same thing but starting on F's play pattern: F, F#, F, E, F (loop)
Same thing but starting on B's play pattern: B, Bb, B, C, B (loop)
Same thing but starting on F's play pattern: E, F#, E, Eb, E (loop)
Same thing but starting on F's play pattern: C, C#, C, Bb, C (loop)
Once you've done all these patterns, you've done all possible diatonic scale combinations you could encounter.
I also made this video on arpeggios and octaves a long time ago, but there should be a few good tips!
If this answers your question, please mark as answered to keep up with maintenance. I wish you the best. :)
By 8ths, you probably mean OCTAVES. Usually played with thumb and pinky (unless you're lucky enough to have a large span and can use ring finger!) It's more of a hand movement than finger movement, hingeing from the wrist. Try r.h. going up and down scales and arpeggios. Watch your thumb, and keep the same span, and the octave note above should be played almost automatically. Try 3 or 4 note tunes to start with. It can also be effective to play the lower note a moment before the upper.