Absolute and Relative Pitch
The ability to instantly identify a pitch by ear without the use of a reference (another note) is called absolute or perfect pitch. Once they learn the names for the pitches they have memorised, people with perfect pitch can identify notes as quickly as we name a colour when we see it. Absolute pitch is rare, and it has its own pros and cons. Having this ability alone does not make them better musicians than those without it. What most musicians build is relative pitch, where a reference is used to identify a pitch according to the interval (distance) between them. When it comes to tonal music, relying on the tonic (first scale degree) as reference is useful, which requires tonic retention, i.e., the ability to retain the tonic in the mind’s ear, like an internal drone.
Solmisation
The system of assigning syllables to scale degrees (solmisation) is common in most cultures, like the sargam (sa re ga) system of India, the solfège (do re mi) system of the West and so on. It is identical to language. Having a common name for something makes it easily communicable, relatable and recallable. It serves a pedagogical and practical purpose. When we say or think of the word ‘blue’, the colour and the feelings or thoughts associated with it appear in our minds. Likewise, we assign certain feelings to each scale degree according to their function (relationship with the tonic, do) and natural tendencies. The goal is to have the scale degree and its unique feeling appear in the mind upon thinking of the syllable, and vice versa. I recommend using chromatic movable do solfège (with do-based minor) if the chosen solmisation system is western. In my opinion, adopting do-based minor is better in the long run for hearing advanced tonal or modal music. Identifying scale degrees and vocally producing them at will is the skill to develop for dictation, sight singing and playing by ear without trial and error.
Scale Degrees
The first step is to practise singing (using syllables) each degree (all 12 notes) over a tonic drone, actively listening and internalising their relationship. This is how Indian classical musicians learn and perform. Spend at least a minute on each degree daily and check your pitch using an instrument. Ascending and descending scales should also be practised. Once tonic retention is built, the drone can be faded out.
Intervals
The next step would be to master intervals within a tonal context. The previous step focuses on the intervallic relationship between the tonic and each degree of the scale, whereas this one is about the intervals between scale degrees themselves. Most students make the mistake of learning to identify intervals using melodies of existing songs, e.g. the first two notes of Amazing Grace form a perfect 4th. This could be a starting point, but the feeling of each perfect 4th within a scale is different. Functionally, scale degree 5 to 1 (in the case of Amazing Grace) feels different from scale degree 1 to 4, even though they are the same interval. A better way is to practise singing, distinguishing and internalising each interval of the same quality and number that occur within a key. Solfège exercises, such as ascending and descending skips of 3rds, 4ths, 5ths, 6ths and 7ths are highly effective.
Chord Quality and Function
Learning to identify basic chord qualities (major, minor, diminished and augmented) and their chordal degrees (root, 3rd and 5th) is another step. This is where a friend or a chord generator comes in handy. Chords are combinations of notes that, much like scale degrees, possess a unique feeling or function within a scale. Internalise them. Eventually, chords will be heard functionally and not just as isolated qualities.
Sight Singing (hear what you see)
Once the ability to identify and vocally produce any scale degree is attained, one can move on to sight singing. Initially, a tonic drone may serve as a crutch. Prioritise note accuracy and rhythm over tempo (as this is not a performance).
Dictation (see what you hear)
The amalgamation of the above skills prepares one to transcribe by ear. Start with melodic dictation and gradually build up to two, then three and four part textures. Listen to the bass, chord quality, root and function to transcribe chords by ear.
Note: Both sight singing and dictation might require mutation (shifting the syllables according to the new tonic) during modulations.
Recommended Resources
Karpinski, Gary S. Manual for Ear Training and Sight Singing. New York: W.W. Norton & Company, 2007.
Bach, Johann Sebastian. 371 Harmonised Chorales and 69 Chorale Melodies with Figured Bass. Edited and annotated by Albert Riemenschneider. New York: G. Schirmer, 1941.