half notes: In musical notation, the half note has a hollow oval head with a stem; it lasts half as long as the whole note, or twice as long as a quatrter note.

half step; semitone: In musical notation, the smallest difference between two pitches.

hammer-on: A guitar articulation technique in which you sound a note by fretting a string with enoungh force to make the string vibrate.

handspan-plus-two-frets method: A method of finding the same notes in different places on the fretboard of a bass guitar.

harmonic minor scale: A musical scale created by lowering by a half-step the third and sixth notes of a major scale.

harmonics: Notes that sound naturally on a string when you lightly touch it at certain points and then strike it with your right hand.

headstock: The part of the guitar that holds the tuning machines.

hygrometer: An inexpensive device that tells you the relative humidity of a room with a good degree of accuracy (close enough to maintain a healthy guitar, anyway).