On a Rhodes piano, the tone bar is a metal length that forms one part of the assembly used for tone generation. It is one of the most recognisable parts of the Rhodes harp, having one tone bar for every key and being very visible when the lid is removed.
The tone bar combined with the tine is called the tone bar assembly. This assembly vibrates to generate a tone that is amplified by the pickup. The way the tine and tone bar combine is similar to the way a tuning fork works: Two lengths vibrate and a frequency is generated between them. The tone bar is the larger, thicker length of these forks.
The tine connects to the tone bar via a tine screw, which can also be used for aligning the tine to the pickup. The tone bar is connected to the harp via the two tone bar screws. Part of this assembly include the tone bar grommets, and the tone bar springs. “Tone bar screw” and “Tine screw” are sometimes used interchangeably.
To improve sustain of upper treble tone bars, tone bar clips can be applied. This works by increasing the mass of the tone bar.
The tone bar is made of an aluminium alloy, which can can chip and discolour over time. Replating the tone bars can improve the appearance, though it can affect the tonal properties due to adding extra mass to the tone bar. Replacing them is usually not necessary, as the tine, if anything, is the most likely to break when struck too hard by the hammer.
