Axel Pfeiffer during Jamulus online rehearsal © Cantamus Gießen

How do online choir rehearsals work without latency?

Conductor Axel Pfeiffer shares his experience on Jamulus


Have you already heard about Jamulus? It is an OpenSource software originally designed for internet jam sessions. In contrast to other programs it enables online group singing and blends the different voices into one coherent sound. Perfect for virtual choir rehearsals – right?

We asked the German conductor Axel Pfeiffer, who already uses Jamulus for online rehearsals with his choir Cantamus Gießen to answer a few questions about his experience with it. He gives some enlightening insights and ends with a clear recommendation – for particular choirs:

        1) Why did you decide to organize your online choir rehearsals with Jamulus? What are the advantages of this program over others?

Compared with other programs that are actually specialized in holding meetings (Zoom, Jitsi, etc.), Jamulus is currently probably the only well usable program that offers the possibility of singing together practically without latency. In addition, the program can be used free of charge. However, this requires some technical prerequisites and suitable equipment on the part of the participants.

        2) How long did it take to become acquainted with the program? How are the rehearsals going at the moment?

Luckily, one of the board members at Cantamus Gießen is an IT professional and also other choir members have profound knowledge in this area. They spent several weeks setting up and using the program, as well as finding out the necessary technical requirements from the choir members. For example, a server was set up especially for this purpose, some information e-mails were written in advance, time slots for the installation were offered, etc.

So after quite a bit of effort to get the whole thing working, we were rewarded with a real feeling of happiness at the first tutti rehearsal (with 20 choir members in Jamulus and 10 more in Zoom). The technology worked amazingly well without any major problems, and it was a wonderful experience after months of rehearsing on Zoom with everyone muted, to be able to sing together properly again, experience choir sound, hear each other breathe, match vocal colors, etc.

        3) What difficulties did you experience in setting up the software?

Most of the choir members were not able to install the software on their computer on their own, but only with the support of our "experts". In addition, depending on the hardware, the installation sometimes worked in just five minutes, but in other cases it sometimes took an hour and a half (including the choirmaster's device ;-) ).

        4) Some of your singers joined the rehearsal via ZOOM instead of using Jamulus. Why was that necessary?

Using Jamulus requires a certain level of technical equipment on the part of the participants: In addition to the fastest possible web access, which should be connected by cable, the program only works on a PC or laptop (i.e. not via cell phone or tablet, as is the case with Zoom, for example). In addition, a microphone of at least reasonably good quality and headphones (e.g. good cell phone headphones with a microphone) should be available.

Since not all choir members have this technical setup (e.g. they live in an old building with poor internet access), some participated in the rehearsal at the same time through Zoom. These then heard the sound from the rehearsal via Jamulus, so that they can still experience a feeling of choir sound in which they can sing along. A few are still working on it or even investing in hardware for it, so the number of our "Jamulists" will surely increase.

Unfortunately, Jamulus has the real disadvantage that you can only hear and not see each other. That's why some have tried to run Jamulus and Zoom at the same time. But first of all you have latency between picture and sound again and secondly most computers are overloaded with using both programs at the same time, so this causes latency again with Jamulus, too.

        5) Does Jamulus make "real rehearsal work" possible? Is it in times of pandemic an adequate alternative for on-site choir rehearsals?

I was myself very surprised by the fact that a real rehearsal was possible without visual contact to the choir members (with a lack of guidance by conductor). Our choir members adjusted incredibly quickly to hearing each other and with pre-counting or appropriate support from me at the piano, after a short time it was no problem to sing pieces in slow and medium-fast tempo at the same time. We haven't tried really fast pieces yet, but even that should be possible with some familiarization. With very demanding pieces in terms of rhythm, one might then come up against certain limits.

It was a real relief to be able to work on the sound of the choir (vocal coloration) again!

The tuning of the sound balance is still a bit difficult at the moment, since there are large volume differences due to the very different quality of the microphones used by the choir members. This can be adjusted to a certain extent via the program, but a few choir members were still only quietly heard.

        6) For which choirs do you think the program suits best?

The program is certainly suitable for choirs that are used to singing more or less independently (younger choirs, pop choirs, chamber choirs, etc.). In addition to the technical equipment described above, the choir members should have a certain computer knowledge. Further it needs some people who take the time to do the setup with the choir members.

Therefore, the program is probably less suitable for older choirs or choirs with not enough choir members who have the technical equipment or experience in using computers. Unfortunately, this is especially true for children's choirs.

        7) Would you recommend Jamulus to other choir members?

In any case, I would absolutely recommend the use of Jamulus. As described above, after conscientious training and preparation, the technology worked very well and reliably and really got us excited. So the work for it is absolutely worth it.

However, every choir director should carefully consider whether their own choir is really suitable for this. Otherwise, failure could also cause frustration among the choir members.

Thank you for the interview!