On any harmonica, the player sounds notes by placing her mouth over the instrument's holes and either blowing or drawing breath through the reeds contained in the harmonica's outer case. Harmonicas come in a variety of types and musical keys. Most beginner lessons and styles are taught using a 10-holed diatonic harmonica. Other types that receive wide exposure are chromatic, tremolo and octave-tuned harmonicas; rarer types include the bass, single and chord models.
Musical Keys and Notes
Harmonicas come in a variety of musical keys. "Keys" are based on the central note of a piece of music'; each involves its own scale based on eight notes starting and ending on the note that defines the scale. C major, for example, "uses a scale that starts on C and uses only the white keys of the piano. In a piece composed in the key of C, the music is likely to end on the note C, and certain combinations of notes based on C will predominate," according to the American Heritage New Dictionary of Cultural Literacy. Harmonicas come in different keys to allow the player to harmonize with other musical instruments by changing harmonicas for different pieces of music. Diatonic harmonicas have holes that play only the notes in the major scale to which they are tuned; chromatic harmonicas play all 12 chromatic pitches.
The diatonic harmonica, sometimes called a "blues harp," is the most basic harmonica model. On a diatonic harmonica, only the major scale notes are played using the harmonica's various holes. The player can "bend" notes ways by manipulating air, mouth and instrument to achieve "bent" sharps and flats between the harmonica's notes, or create a "fake bend" that only bends the existing note without achieving a new note. The diatonic harmonica is usually used in blues, folk and rock music.
A chromatic harmonica has a button on the side; with the button open, the harmonica plays notes in a major key. With the button depressed, the harmonica supplies the sharps and flats in between the pitches of the major scale, allowing the player to play any note. The chromatic harmonica does not bend notes well, so diatonics and chromatics achieve different sounds and work best for different musical styles. The chromatic version is typically used in jazz or classical music, but is occasionally found in all musical styles.
Other Harmonica Types
Some of the most common alternate harmonica types include tremolo, octave-tuned and chord harmonicas. Tremolo harmonicas consist of two rows of holes with two reeds of the same pitch suspended one above the other. When a tremolo is played, the vibration of the two identically tuned reeds next to one another creates a vibrato or "tremolo" effect. Octave-tuned harmonicas, like tremolo harmonicas, have two rows of holes and two reeds suspended one above the other. The two are tuned one octave apart, creating a rich sound. Octave and tremolo harmonicas are most often used for special effects and can only play very basic melodies. Other, rarer, harmonica types include bass harmonicas, which are massive instruments with a wide range of notes and effects; "single" harmonicas (both alto and soprano) that are laid out in two rows matched to piano keys with the "white" notes on the bottom row and black-key sharps/flats on the top row; and the chord harmonica , which is very long and laid out with one or two reeds in clusters of four-note holes that allow the player to blow chords. Chord harmonicas are available in 6-, 20- and 48-chord versions, among others.
- Jupiterimages/BananaStock/Getty Images