What is Velocity Sensitivity?

It’s impossible to avoid the term ‘velocity sensitivity’ when you’re looking at electronic keyboard instruments such as pianos, keyboards and synthesizers. In this blog, we explain what velocity sensitivity is and what you can use it for.

What is Velocity Sensitivity?
Photo: Casio GP-310 key mechanism

What’s Velocity Sensitivity?

Velocity sensitivity refers to the mechanism that allows the keys to respond to the force or speed with which they’re pressed. In other words, keys react differently when they’re played in different ways. Playing a keyboard gently will result in softer sounds, while literally playing harder produces more volume. By varying the ‘velocity’ at which you play notes, you enrich your playing with expressive dynamics, which is essentially the difference between louder and quieter notes.

How Does it Work?

The concept of touch-sensitive keys comes from the world of acoustic and grand pianos. The hammers inside these instruments strike a string, causing vibrations to create sound. The harder you press the keys, the harder the hammer hits the string and the louder the note will sound. In electronic instruments, sensors are fitted instead to register the speed at which keys are played. The first sensor registers which key is pressed while a second sensor takes note of how fast it came down, calculating the speed and converting it into either a louder or softer sound. In most cases, notably digital pianos, multiple sound samples are used for this. After all, acoustic pianos also sound differently when played loudly or gently to change the timbre. Keep in mind that while touch-sensitive keys can be found on most keyboard instruments, cheaper models tend to lack this feature.

How and When to Use It?

As already mentioned, velocity-sensitive keys allow you to play softer and louder; something that’s not only important when you’re using sheet music to play either classical or modern pieces of music, but also when you’re playing your piano using string section or wind instrument sounds. Not all keyboard instruments come with velocity-sensitive keys though. Organs and older synthesizers actually have a volume control or volume pedal, and if your keyboard or piano is loaded with synth or organ samples, you should be able to turn the velocity-sensitivity off altogether to get an authentic playing experience. Moreover, most touch-sensitive keyboards are adjustable, so you’re free to experiment and find what best suits your style.

Weighted Keys

Since the inner keyboard mechanisms of a genuine acoustic upright are remarkably complex, velocity-sensitivity isn’t the only function that simulates the action of acoustic pianos. This thickness of the piano strings also affects the striking of the hammers and, to simulate this effect, keyboards are often fitted with weighted keys. Here, a combination of tiny weights and springs create realistic recoil. Some more advanced digital pianos already even feature a real hammer mechanism to match the feel of an acoustic model. However, you won’t find weighted keys on most regular keyboards, simply because these instruments haven’t been designed to simulate pianos and instead come loaded with an extensive collection of different sounds.

Do you have any questions or remarks about velocity sensitivity? Don’t hesitate to leave them in the comments below!