JamKazam for on-line jamming

Hi everyone,

You may have heard about, or perhaps explored yourself, JamKazam as a possible means to jam with others while we wait out the coronapocalypse. I’ve been using it for a week or so now, as have many others, and I have had some delightful jams with musicians all over the country. It CAN work, though it won’t always work and it won’t work for everyone. (The interface is clunky and a bit inconsistent right now.) Also I’m under the impression that the developers are working continuously on it now, and making improvements all the time. If you tried it in March and it didn’t work for you, it’s a whole different ballgame now - try it again.

So if you’re interested in on-line jamming, do check out JamKazam. Please don’t be intimidated by how “tech” it sounds - it’s not difficult if one takes it step by step, although it does require a high speed Internet connection with an Ethernet cable (not wi-fi), and it appears to require (I don’t know of anyone not using these) an audio interface, microphone for acoustic instruments, and headphones to eliminate feedback. If you have an electric instrument I’m not familiar with how that changes the requirements.

If there’s enough interest on this forum I will post a more detailed, step-by-step guide. (BTW, I am not affiliated with JK or with Strum Machine! I’m just a retired lawyer who took up bluegrass fiddle a year and a half ago and may someday be good enough that everyone doesn’t run out of the room.)

It’s also worth noting, and actually why I came here (thanks for the suggestion, Luke!), that, in last night’s bluegrass session with musicians from coast to coast, we used Strum Machine for our bass because we didn’t have a bass, and it worked really well. One of the jammers just fired up the chosen song on Strum Machine and voila, we had a bass. :slight_smile:


I second this, @AnneTaylor! I’ve been on JamKazam for a few months now and am having a blast with it. I’ve met (virtually) some nice people who I’m jamming with regularly now. And, best of all, all my bandmates are now on JK and we’re practicing twice a week after not being able to rehearse or play gigs for several months.

As you said, it’s not perfect and takes getting used to (the speck of latency and not seeing each other), but I’ve found that the more I do it, the more comfortable it becomes.

A couple times, we patched in the Strum Machine to help us keep time and it worked better than the built-in metronome on JK.

If anyone is interested in a Strum Machine Community meetup on JamKazam, I’d be up for it.


Yes, Strum Machine and JamKazam (and Jamulus) are like peas and carrots. Meant be be used together. Currently, I am having as much or more fun with Jamulus than JamKazam. These two programs, along with SM, are great and work together so well!

I read that Jamulus is not real time - is that true? If it’s true, how does that work; and how would a melody instrument (I play violin) work?

@AnneTaylor really neither JamKazam nor Jamulus are true “real time”. Internet latency is roughly 1ms per 100 miles of physical distance. These software packages try to compensate for this latency by sending the audio signal out to each participants ears such that the music is synchronous. To maximize enjoyment of either, I ensure that I know who is responsible for maintaining the song tempo. Let’s say that person also runs Strum Machine! Everyone else focuses on SM and I turn everyone else’s volume down (except for the source of SM or the tempo keeper). Knowing that limitation, it is still quite fun, and SM is a huge help to the fun on either platform.

How are you patching Strum Machine into Jamkazam. I have tried by using another Tablet with SM into a mixer and then into JKam, but that requires two computer units. I have tried playing SM in one window and JK in another. It works but I have not volumn control for the SM when everything comes out the output of the Focusrite Scarlett 2i2. I guess I could put the instrument and mic into a mix and into interface channel one and the tablet into channel two. Although that is no different than just putting into the external mixer. I would like to run everything off my computer screen. Anyone have a good solution?

This is for Mac only, not sure how you can do it in Windows:

The key is using a virtual device signal routing tool. The free one that I use is Blackhole. You will use this to route your default sound output device into Jamkazam.

  • Download and install (this is an open source tool on Github). It will create a virtual sound interface device with 16 channels in and 16 out.

  • In the Mac Midi setup for Audio Devices create a Multiple Output device (use the + sign at the bottom of the window to add a device) . Select the default system output device and the Blackhole device in the list presented in the panel and turn on “drift correction” checkbox for the Blackhole device. The default (or Built in) output must be selected first.

  • Create an “aggregate device” in the same Mac Midi Audio Devices setup and select input entries for the Scarlet 2i2 and the Blackhole device (in that order). In my setup I set the Clock Source to be Blackhole and set Drift Correction on for the 2i2. This is a bit of a gray area to me but this works in my setup.

-Make sure all the devices in this setup have the same sampling rate specified (e.g. 48K).

  • Now go to Jamkazam Audio Setup and select the aggregate device as your input. Select the 2i2 as the output. Save this configuration.

  • Start a Jamkazam session and you will be able to hear your Strum Machine in the mix (and so will anyone else in your session). The sound will also still be coming from your Mac speakers so you will need to mute them when using this configuration so that they don’t get picked up in your microphone. You can do this in the same Audio Devices setup utility by selecting Built in Output and checking the box to mute Master.

This is a fairly terse tutorial for a somewhat involved configuration but I can provide some more detail if you need it. Didn’t want to write an encyclopedia only to find out you are using a Windows PC :wink:

Whoops, forgot last step. In JK you must select not only the first 1 or 2 channels of the aggregate device which represent the 2i2 inputs, but also channels 3 and 4 which will now contain the signal from your Mac output (Strum Machine included). Do this by adding an input track in the JK Audio Setup dialogs and assigning channels 3 and 4 from the aggregate device.

Win 10 has a volume control for Chrome browser. I just play it in there through a Chrome window and it also goes out through my 2i2 to Jamkazam. You can also make an mp3 in Strum Machine beta now and record it that way. Then just use your audio player and your speaker icon through 2i2. there is also a Windows based virtual auto mixer for Win 10, I think the name is Voicemeter Banana. I have not tried. it, but a slimmed down concept is already in Win 10.