People can learn to play an instrument. Probably the most common for complete beginners is the piano or keyboard, the guitar, or the recorder (which is certainly the cheapest to buy). After they have learnt to play scales, play simple tunes and read the simplest musical notation, then they can think about which instrument for further development. They should choose an instrument that is practical for their size. For example, a very short child cannot play a full size double bass, because the double bass is over five feet high. People should choose an instrument that they enjoy playing, because playing regularly is the only way to get better. Finally, it helps to have a good teacher.