Solfs

Solfs, also known as "sound letters" or "note names," are a system used in music education to represent the pitches of a musical scale. The most common solfège system uses the syllables do, re, mi, fa, sol, la, and ti (or si). These syllables are derived from a medieval Latin hymn, "Ut queant laxis," where each line began on a successively higher note of the scale, and the first syllable of each line was used.

The primary purpose of solfège is to aid in sight-singing and ear training. By assigning a distinct syllable to each scale degree, musicians can develop a better understanding of melodic intervals and harmonic relationships. This system helps singers and instrumentalists internalize the sound of each note relative to the tonic (the "do" of the scale).

There are two main approaches to solfège: fixed do and movable do. In the fixed do system, "do" always represents the note C. In contrast, the movable do system assigns "do" to the tonic of whatever key is being played. This allows the same syllables to represent different absolute pitches depending on the key. Movable do is widely used in many pedagogical approaches, particularly in the United States and Britain, as it emphasizes the relationship between notes within a given scale. Fixed do is more common in some European countries and is often used in professional settings where a direct association with absolute pitches is beneficial.