Electric guitars and bass guitars have to be used with a guitar amplifier and loudspeaker or a bass amplifier and speaker, respectively, in order to make enough sound to be heard by the performer and audience. Electric guitars and bass guitars almost always use magnetic pickups, which generate an electric signal when the musician plucks, strums or otherwise plays the instrument. The amplifier and speaker strengthen this signal using a power amplifier and a loudspeaker. Acoustic guitars that are equipped with a piezoelectric pickup or microphone can also be plugged into an instrument amplifier, acoustic guitar amp or PA system to make them louder. With electric guitar and bass, the amplifier and speaker are not just used to make the instrument louder; by adjusting the equalizer controls, the preamplifier, and any onboard effects units (reverb, distortion/overdrive, etc.) the player can also modify the tone (aka timbre or "colour") and sound of the instrument. Acoustic guitar players can also use the amp to change the sound of their instrument, but in general, acoustic guitar amps are used to make the natural acoustic sound of the instrument louder without changing its sound that much.
The shape of the neck (from a cross-sectional perspective) can also vary, from a gentle "C" curve to a more pronounced "V" curve. There are many different types of neck profiles available, giving the guitarist many options. Some aspects to consider in a guitar neck may be the overall width of the fretboard, scale (distance between the frets), the neck wood, the type of neck construction (for example, the neck may be glued in or bolted on), and the shape (profile) of the back of the neck. Other types of material used to make guitar necks are graphite (Steinberger guitars), aluminum (Kramer Guitars, Travis Bean and Veleno guitars), or carbon fiber (Modulus Guitars and ThreeGuitars). Double neck electric guitars have two necks, allowing the musician to quickly switch between guitar sounds.

Instructor ProfileArlen RothThe King of All Guitar TeachersMusic lesson pioneer Arlen Roth is the quintessential guitarist. An accomplished and brilliant musician — and one of the very few who can honestly say he’s done it all — Roth has, over the course of his celebrated 35-year career, played on the world’s grandest stages, accompanied many of the greatest figures in modern music and revolutionized the concept of teaching guitar. Read More...Lessons Wes Montgomery-style Octaves
In 1977, the Guitar Institute of Technology (GIT) revolutionized contemporary music education with the first full-time program to offer hands-on professional training for the electric guitarist. Over three decades later, MI remains the leader in guitar education, besting other colleges for guitar players, with a unique system that combines technical, creative and professional development in a performance-based program.