The bandoneon is a large, accordionlike instrument capable of playing diatonic music, or music using all 12 notes of the chromatic scale. The bandoneon is best known for its use in tango music from Argentina, but it has recently garnered interest in the pop music world, particularly after being used by alternative favorite Arcade Fire. The bandoneon has a large repertoire, including dance music and pieces by Argentine composer Astor Piazolla.
Sit on a chair with your back straight and feet flat on the floor. Hold the bandoneon across your lap with your hands through the hand straps. Keep your wrists loose and relaxed. Practice opening and closing the bandoneon without pressing any keys to get used to the motion. You want an even tone throughout.
Refer to the fingering chart. Begin learning scales with C major. Play the scale from C2 (the lowest C) to C6 (the top C). Then move on to D major. Play all scales and arpeggios, major and minor, every day. Scales and arpeggios will teach your fingers where all of the buttons are. Use just your fingers---not your whole hand---to reach each note. Bandoneon player and teacher Ben Bogart writes, "To play well, and to be able to relax your wrists, you have to learn to articulate notes from just your fingers. There are many exercises to help you achieve this, the one that worked the best for me was to play a scale repeating each note first two times, then four times, then eight times. After a few days/weeks of this you will start to notice that your fingers are gaining independence and working on their own."
Work your way through a method book. There are several method books available for the bandoneon, including the Don Benito method, the Mele Metodo de Bandoneon and the Fernando Maguno method. Practice each exercise and piece until it is smooth and musical.
Play lots of different kinds of music. Bogart suggests playing Bach pieces arranged for the bandoneon as a way of improving technique and learning the instrument's capabilities. Bogart also offers arrangement of traditional tango tunes on his site. Don Benito also offers arrangements for the bandoneon.
Take lessons. As you get more accomplished with the basics of bandoneon playing, you might want to consider taking a few lessons or playing in a master class for an experienced player. Many large cities have tango bands that include bandoneon players, many of whom give lessons.
Play in a group. Nothing improves your sense of the music and ability to improvise and follow chord changes than playing with a group. Ask around at dance studios that teach the tango about their bands to find people to play with.
Practice daily. Practice slowly until the notes are clear and even.