Learning to identify melodic intervals by ear
In music, an interval is the difference between two notes and, in Western music, there are 12 of these. They are named as follows.
- Minor second (Semitone)
- Major second (Whole tone)
- Minor third
- Major third
- Perfect fourth
- Perfect fifth
- Minor sixth
- Major sixth
- Minor seventh
- Major seventh
- Perfect octave
Melodies are formed by playing these intervals sequentially. There is a lot of value in learning to identify these melodic intervals by ear. It is the basis of playing by ear, for instance. If you know what intervals you heard, it's easy to play that on an instrument.
Unfortunately, listening to sounds in this way is not common outside of music, so developing this skill can take time. But learning to hear intervals can be made easier if you use a good approach. There are several options including melody association and learning to sing the interval. I recommend trying both.
As the second note can be higher or lower, there are 24 melodic intervals to learn. A common approach used to do so is to associate them with songs or tunes. For example, the first two notes of 'Greensleeves' is an ascending minor third. If you focus on the interval and the following notes a connection can be built. Upon hearing the interval, the following notes of the tune will play back in your mind. So to differentiate the intervals, simply associate each one with a different tune.
Choosing effective associations
Most explanations of the association technique give large lists of 'common' tunes. However, what is common to one person is foreign to another. Don't use something just because you see it on a list. Where possible, it is better to make use of the music you already know.
Study the music that you play regularly and identify the prominent intervals, such as what it begins on and those in prominent places. Make a list of these tunes, the intervals, and whether the interval is ascending or descending.
There are going to be gaps in this list but don't worry about it. As you work forward, pay attention to new music you like and, gradually, the gaps will fill. Some intervals like the tritone and minor second are very distinct in sound. You may be able to identify them without an association.
Developing the association
A good way of developing associations is to learn intervals in pairs, as this lets you test your recognition, but which intervals? When you approach a new task, your mind does not know how to deal with it. To maximize your chance of success, you want to pair intervals that are distinct. Choose two intervals from your list that are far apart and of different types, such as the minor second and perfect fifth.
Look for these intervals in the music that you already know, then learn to play the fragment on your instrument, playing the interval and the following 5 or 6 notes of the tune. Keep playing it and listening to how the interval sounds with the following notes. Once you have it clear in your memory, play only the first two notes, the trigger interval. Keep thinking of the following notes in your head. Do this over several days, as sleep is a critical part of the learning process.
You need to practise these associations in a wide range of keys and octaves. A MIDI keyboard is an ideal instrument for doing this as it can be transposed at the push of a button without changing your fingerings. You don't have to play an instrument well for it to be useful as a learning tool. If you do practise this with an ocarina, make sure you are playing in tune. Play ocarinas in different keys and octaves.
Note that this approach is different from the typical practice of pairing close intervals, such as a major and minor third. As these are only a semitone apart, it is quite easy to mis-hear them at first, leading to frustration.
Testing your recognition
Obviously if you play an interval yourself, you will know what you just played. Thus, to test your recognition, you need someone or something else to play the intervals for you. If you have access to a teacher, or a friend that you practise with, get them to play your intervals and you can identify them. They will then tell you if you are correct. If both of you are learning the intervals, you could turn this into a game. See who gets the most correct.
Another option is to use a practice tool. Tools like Gnu Solfege and various mobile apps exist that play intervals randomly. They present an interface so you can select what you think it was and tell you if you were correct. Many of these apps follow the typical close interval pairing in their pre-configured exercises. For the reasons that were explained above, it is important to use a tool that allows you to configure the intervals yourself. In Solfege, this can be done by selecting 'configure yourself' then 'melodic intervals'.
Listen to the interval. If you don't hear the associated tune in your head, imagine your reference tunes against it to see which one fits. Don't be afraid to repeat the interval. If you make a mistake, don't worry about it. Just go back to the previous step and spend more time playing it. You may only hear the tune weakly at first. In a few more days, you'll start to strongly hear the notes of your associations, though if you are getting no hint of progress, try a different association.
I have noticed that I fatigue rapidly while doing this. At first, I can hear intervals easily but, after only 5 minutes, I disengage and my errors skyrocket. Consequently, I find it best to work in very short sessions of a few minutes several times a day. Also be aware that even if you are not consciously aware that you are learning, your subconscious mind is still taking notes.
Learn to sing the interval
Another approach is to learn to sing the intervals. As both your vocal cords and your ears are attached to your brain, learning to sing the intervals is a great way of internalising how they sound. If you can sing them reliably, you know them, and so it's much easier to associate a name to that knowledge. Don't worry if your voice isn't very good. It really does not matter how well you can sing as you are not performing, just using it as a tool to develop an intuitive feel for the intervals.
To begin, simply sing long vowel sounds against a tuner—A, E, O, or U. Vary your pitch up and down to find the extent of your vocal range, using a chromatic tuner to measure it. Don't stress yourself; if your voice starts getting very thin sounding, raise or lower the pitch until you reach a note that sounds clean. Make a note of the highest and lowest note.
Pick a note around the bottom of your range and chant it over and over again. You should aim to keep the pitch of this note in tune using your tuner. If it isn't in tune, make a conscious effort to correct it. Being able to hold a note stable is essential. You cannot sing an interval between notes unless the notes are stable. If you have not done this before, you may not be able to keep it on pitch for a few days or weeks. This is OK. Keep working on it in short sessions and you'll get there.
Once you can hold your pitch stable, learning to sing a semitone is a good place to start. As it is the smallest interval commonly used in music, it can be used to navigate your vocal range. Simply ascend or descend by multiple semitones in sequence. You can then use this to find the notes in a wider interval.
From your base note, raise your pitch so you are a semitone higher on your tuner. Practise this note on its own until you can hold it stable, then try singing the interval between them. If you land out of tune, don't worry about it. Just try again. As you sing the interval, think of your song associations following notes, as this will help to strengthen the attachment.
You can continue learning other intervals in the same way. Once you can sing the interval ascending, try singing it descending.
Unfortunately, listening to sounds in this way is not common outside of music, so developing this skill can take time. In addition to the two methods given above, any practice you can get with listening to sound will help. For example, if you have a guitar, ukelele, or similar instrument, try learning how to tune it by ear. If you stick with it, you will gradually get better.