In music terms, intonation refers to pitch accuracy – whether a note is played/sung ‘in tune’. When you tune your instrument at the beginning of a practice session, you are adjusting the pitch of a particular note (for example an open string) until it matches a particular reference tone. Whilst you are playing, you are constantly checking and potentially adjusting to ensure that the notes you play are in tune. Having good intonation is an essential part of playing a musical instrument well.
As a string player, below are a few of the techniques that I use to improve my intonation:
Playing through scales is a good way of checking your intonation without having to worry about the other components of playing a piece of music (tempo, rhythm etc). When practising my scales I use the Scales Practice app to ensure that I am playing them correctly. You can pick a scale, set a low tempo and then get the app to play the scale note by note. I play my instrument against these reference tones and adjust where necessary. Being able to play scales in tune helps with my general music playing as you will often find scale patterns in pieces of music.
I find playing with someone else very helpful for checking my intonation (although you are relying on them playing in tune!) and often play with a piano accompaniment. I might start by getting the piano to play the same notes that I am, and then progress to them playing intervals of a fifth, third or octaves so that I can practice listening for the correct intonation. If I don’t have someone to play with, I will look for a recording of the piece and listen to that.
If I come across particular notes that I am not sure about (usually high up on the figure board!) and don’t have a piano to check against I will play them against my tuner to make sure that I have them right.
I find that practising a note against an open string can help me to hear whether it is in tune or not. I will often start playing octave intervals (e.g. play an A on my D string against my open A string), and then progress to other intervals such as thirds. I also practice interval scales to help improve my intonation.