In music, an interval is the distance between two notes or two pitches. For example, the distance from C to D is a second, since this involves two “whole” notes (or whole tones). The distance from C to E is a third (3 notes – C,D, and E, skipping over D), and the distance or interval from D to A is a fifth – it involves five whole notes. Traditionally, chords are spelled in intervals of thirds. Musicians are trained to recognize intervals quickly. Many musical directors contend that a knowledge of singing in solfege (or solfeggio) will lead a person to recognize intervals quickly in written music, thus making sight reading easy and fun. When we sing the Italian “Sol, Mi, Do” in Musikgarten, we are singing a third, and then another third. When we sing “Do, Sol,” we are singing a fifth, such as D to A. Reverse that to “Sol, Do,” and it is still a fifth.
Some familiar tunes can help you learn several musical intervals: “Oh, When the Saints” begins with a major third. “Here Comes the Bride” begins with a perfect fourth. Twinkle, Twinkle Little Star” begins with a perfect fifth and “My Bonnie lies over the Ocean” begins with a major sixth.
When I refer to “do” - pronounced dough - I refer to the moveable do on the piano. “Do” can be D, or C, or G, or F, etc. Consequently, all the other solfege syllables move along with “do.”