A needle, LCD, or regular LED type tuner uses a microprocessor to measure the average period of the waveform. It uses this to then drive the needle or array of lights. The array of lights from LED that appears to move to left or right seems better than the meter needle of the early meter tuners. When the musician plays a single note, the tuner senses the input from the microphone or input jack (from an electric instrument). The tuner then displays the input frequency in relation to the desired pitch and indicates whether the pitch of that note is lower, higher, or approximately equal to the desired pitch. With needle displays, the note is in tune when the needle is in a 90° vertical position, with leftward or rightward deviations indicating that the note is flat or sharp, respectively. Tuners with a needle are often supplied with a backlight, so that the display can be read on a darkened stage. An early (1970s) meter needle tuner seemed inferior (more difficult to use) than the more expensive light emitting diodes (LED) type.

The question of who makes an electronic tuner, should be more of Who doesn't make an electronic tuner.. With that in mind here are a few recommendations that I (Curt) has used over the years.

• Planet Waves by D'Addario — Headstock Tuner. Each of my Ko'olau CS Tenor ukuleles have one of the D'Addario Micro Headstock Tuner permanently attached to the headstock.

Strobe tuners (the popular term for stroboscopic tuners) are the most accurate type of tuner. There are three types of strobe tuners: The mechanical rotating disk strobe tuner, an LED array strobe in place of the rotating disk, and "virtual strobe" tuners with LCD displays or ones that work on personal computers. A strobe tuner shows the difference between a reference frequency and the musical note. Even the slightest difference between the two will show up as a rotating motion in the strobe display. The accuracy of the tuner is only limited by the internal frequency generator. The strobe tuner detects the pitch either from an TRS input jack or a built-in or external microphone connected to the tuner.

• Peterson Strobe Plus
• Planet Waves
• Sonic Research

A tuning fork is a simple, two-pronged metal instrument that is designed to produce a specific pitch when struck against a surface. It is commonly used as a reference pitch or standard for tuning musical instruments, particularly those with fixed pitches, such as pianos, guitars, and violins.

An Old School method of tuning.

The D'Addario Tuning Fork is available in A (44oHZ) and E (329.6HZ).

A pitch pipe is a small handheld device used to produce specific pitches or tones as a reference for tuning musical instruments or vocalists. It is a compact and portable tool that is often used in acapella singing groups, choirs, and situations where a quick and convenient tuning reference is needed.

With the advent of electronic tuners and smartphone apps, pitch pipes and tuning forks have become less common in certain musical contexts. However, the pitch pipe still finds use in acapella singing groups, choral rehearsals, and situations where a simple and portable reference for pitch is needed without relying on electronic devices.