So a friend and I have been trying to jam, but there is a huge latency issue. Not sure what could be causing this.

When there are questions about latency they are usually about one of two things:

1. Hearing yourself - or recording/playback latency with your soundcard. 5-10 milliseconds latency is typical with a normal computer and external USB soundcard (Focusrite, m-audio, Alesis, etc). That is low enough that you don't feel a delay between playing a note and hearing it.

If you are playing a note and not hearing yourself immediately then adjusting the latency in jammr's audio settings can help. In the worst case you may need to try another soundcard.

2. Hearing others - jammr solves internet latency using an interval-based approach to online jamming. This lets you jam with people around the world without unpleasant lag.

The way it works is that you set the Beats Per Interval (BPI) and jammr buffers the audio for the duration of the interval. Other people hear what you played last interval, you hear what people played last interval.

This means jammr is not “real-time”, instead it is “live” and unaffected by lag. It doesn't matter that you aren't playing in real-time as long as you keep jamming in the same key or stick to a chord progression.

Think about this example: It doesn't matter if you solo over a 4-bar progression like Am | F | G | Am that I'm playing right now or the same chords I played last interval. Your notes will still “fit” because you're playing over the same chord in either case. This is the trick to interval-based online jamming.

The only thing you need to do is set the BPI to the length of your chord progression. Playing 12-bar blues? Set BPI to 4 x 12 = 48 beats. Simple 3-bar progression? Set BPI to 4 x 3 = 12. And so on…