Pen2Bow Turns Apple Pencil Into A Violin Bow MIDI Controller

Pen2Bow is a violin bow MIDI controller for iOS that lets you use the Apple Pencil to create bowing gestures for virtual instruments.

In the video above, Pen2Bow is demonstrated with SWAM Violin, a physical modeling virtual instrument.

It takes advantage of the sensors in the Apple Pencil and generates 4 continuous MIDI controllers: velocity, force, tilt and orientation. These can be assigned, for example, to expression, vibrato, bow pressure and position on the bridge to drive a virtual violin – or to any other parameter to drive synthesizers.

Pen2Bow recognizes linear as well as circular pencil motion. Circular motion enables the infinite extension of the bow that otherwise would be limited in length. This frees the user from constantly thinking about performing bow changes in order to prevent the bow from running out.

Pricing and Availability

Pen2Bow is available now for US $8.99.

18 thoughts on “Pen2Bow Turns Apple Pencil Into A Violin Bow MIDI Controller

  1. just to be a devils advocate here ,why not learn a violin .when your fans find out you play the pencil they will laugh and laugh loud.

  2. does anyone recognize the tune the demoer is playing at around 1:00? It’s very familiar but i can’t remember the names.

  3. I’ve been playing violin for almost 10 years now, and as a player and music composer using the best string libraries out there, I have to say that anything apart from a real violin bow in the hands of a real player will never get even closer to a real sound.

    1. You sound like old drummers that used to complain about the introduction of drum machines. The truth is talented producers will no only be able to produce adequate emulations of violins superior to that of modern sample only based instruments, all without the need for years of practice, expensive instruments and recording studios, more excitingly they will produce synthetic creations that you will never be able to achieve on a physical instrument. Instead of hating, try participating. Perhaps you will find your learned skills will make you more naturally adept to the new technologies?

  4. Thank you all for your interest and feedback! We released update 1.0.2 that includes some of the features that users requested to make Pen2Bow more powerful when used with synths. Here is a video introducing what’s new: https://youtu.be/lch_I9Y3SEg.

    Updates in detail:

    – Added a settings page. It includes sensitivity and range adjustment for the 4 MIDI controllers.

    – Added a touch piano keyboard. Virtual instruments can now be played without the need for an external MIDI keyboard.

    – Added a refresh button for the MIDI device list. Pen2Bow no longer needs to be restarted in order to detect new MIDI devices.

    – Added smoothing option for the pencil velocity. Pen2Bow is very sensitive and picks up the smallest fluctuations in pencil speed. When used with string instruments, this greatly adds to the realism. In the case of synths however, those micro fluctuations might be less desirable. Therefore now there is an option to dampen those fluctuations (version 1.0.1 and higher).

  5. This seems to work well only with string plug-ins that interpret velocity a particular way. I tried this with eastwest Hollywood Solo Violin and Solo Cello, but could not get them to articulate the way they do in the product videos. It would be nice if the developer offered suggestions for other apps, but he only seems to demonstrate the violin articulations with SWAM violin, which is nice if you own SWAM, but if you own any other solo string product you may have trouble getting it to respond correctly, as I did.
    I still think this is a cool product, but it won’t be useful to me as a violin controller unless I actually purchase SWAM violin, apparently.

    1. Dear C.S.Johnson. You can use Pen2Bow with any string library and even with synthesizers. If you want to use Pen2Bow with a non-SWAM sample library you have to switch off the bipolar velocity mode. In bipolar mode, a value of 63 represents no bow movement, 127 represents maximum velocity in one direction and 0 represents maximum velocity in the other bowing direction. This allows transmitting information about the bowing direction and velocity within one single midi controller. Unfortunately only the SWAM family of string instruments currently support this bipolar option. I hope that other developers of string libraries will realize the impact of bowing controllers like Pen2Bow and provide that option in the future. Until then, you have to switch bipolar mode off in Pen2Bow. In that case, a value of 0 represents no bow movement and a value of 127 represents maximum velocity, like a normal mod wheel.

  6. It’s a nice idea! Except scythe,is there any violin/cello instructment app can control by Pen2Bow on ipad ? Only can match SWAM Violin?

    1. Pen2Bow can control any virtual instrument that supports MIDI input. There are many synth Apps beyond scythe that can be used with Pen2Bow. Make sure to check in their manuals if they accept continuous controllers (CCs). As far as string instruments go, I don’t think there is any App that offers comparable performance to the SWAM family of instruments. But if you only need to control expression with the pencil velocity, then probably most virtual string instruments would work with Pen2Bow.

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