Tuning gauges are tools used to measure and adjust the pitch of musical instruments. They help musicians ensure that their instruments, such as guitars or violins, are in tune by providing a visual or audible reference for the correct pitch. These gauges can come in various forms, including electronic tuners, clip-on devices, and smartphone apps. By using a tuning gauge, musicians can easily identify whether a string or note is sharp, flat, or in tune, making it easier to achieve the desired sound in their performances.