How Musical Instruments and the Voice Produce Sound

How Sound is Produced in Music

String Instruments

In string instruments, the sound is produced when one or more strings begin to vibrate. This vibration can be caused by:

• Rubbing the strings (bowed strings)
• Plucking the strings (plucked strings)
• Hitting the strings (hammered strings)

Wind Instruments

In wind instruments, the sound is produced when the air starts to vibrate inside a tube.

Percussion Instruments

In percussion instruments, the sound is produced when a solid object, which is usually struck, begins to vibrate.

The Human Voice: A Natural Wind Instrument

We are essentially a wind instrument. The voice is produced by the vibration of the vocal cords, which is caused by the pressure of the air we exhale. There are three steps in voice production: breathing, vibration or phonation, and resonance or amplification.

Breathing

• Inhale: The first step is to take in air. Once we have taken the air, it goes to our lungs, which expand, pushing the diaphragm down. At this moment, the diaphragm pushes the internal organs and the belly.
• Exhale: We begin to expel the air, controlling this process with the abdominal muscles. The diaphragm goes up, pushing the lungs and forcing them to allow the air to exit.

Vibration or Phonation

The air we have expelled goes through our trachea and arrives at the larynx, where there are two bodies called vocal cords. These begin to vibrate, producing the sound.

Resonance or Amplification

The sound produced by the vocal cords would be very soft and would barely be heard if it wasn't amplified. This sound is amplified in several cavities we have in our bodies, such as the trachea, the larynx, the mouth, the nasopharynx, and the sinuses.

Voice Classification

Female Voices

• Soprano
• Mezzo-soprano
• Alto

Male Voices

• Countertenor
• Tenor
• Baritone
• Bass

Orchestral Instruments

Strings

• Bowed Strings (cuerda frotada): Violin, Viola, Cello, Double Bass (contrabajo)
• Plucked Strings (cuerda pulsada): Harp, Harpsichord
• Hammered Strings (cuerda martilleada): Piano

Woodwind (viento madera)

• Piccolo, Flute, Oboe, Clarinet, English Horn, Bassoon, Contrabassoon (contrabajo), Saxophone

Percussion

Membranophones (Drums)

• Timpani, Bass Drum, Snare Drum, Bongos

Mallet Instruments

• Xylophone, Metallophone, Vibraphone, Marimba, Glockenspiel, Tubular Bells

Small Percussion

• Cymbals, Triangle, Gong, Cabasa, Maracas, Woodblock, Claves, Temple Block, Castanets, Ratchet, Shaker