Virtual choir and virtual band videos in Reaper

Dr Jonathan Kemp of Kemp Strings and the University of St Andrews has been helping musical people all over the world to connect during the social isolation of the COVID-19 outbreak by writing code the enable collaboration videos to be created in REAPER digital audio workstation (DAW) software. Dr. Kemp’s code is now built in to REAPER under as of the 16th of June 2020 “REAPER 6.12c: Black Lives Matter” update under Public Domain license as the new “Combine: Grid of videos” preset for the Video Processor effect.

Check out his guide:
How to make a Virtual Choir or Virtual Band Video in Reaper (grid of any number of video files)

You no longer have to copy and paste and save the code (which is a new development in comparison to the video guide above). Just make an empty track as track 1 and go to FX>Video Processor and select the new “Combine: Grid of videos” preset. Put the videos you want in the grid in tracks 2 onwards. A grid of videos is produced (visible in the View>Video) and the code automatically allocates column and row numbers to include all the videos in the project. Easy to use controls appear for dragging parameters to give some great customisations and these can automated for some cool effects. Check out the development of the code in Jonathan’s Video Code on the Reaper Forum.

The code has been used to generate many posts including this video from Teannaich, Jonathan’s rock ceilidh band which also features Kemp Strings Lumped 45s on his Sadowsky bass and Kemp Strings Standard 10s on Dr. Mark Neal’s Fender Telecaster.

9 thoughts on “Virtual choir and virtual band videos in Reaper”

  1. Hello Jonathan,

    I came across your channel today, and wanted to thank you for the wonderful videos! Really helpful to a beginner editor like me having to make videos for the first time!

    I’m hoping you can help me with a question regarding Reaper and video editing. I need to make one of those virtual orchestra videos for my school orchestra, and would love to use Reaper for this, as it’s a lot faster than Lightworks which I’ve been using. I’ve been editing the audio in Audacity with poor results – I’m totally useless with proper editing, and would like to hone my skills in this.

    My question: how would I use your code on the reaper videos to make a 20 panel orchestra video, if the videos are different orientations? Some of the kids sent portrait and some sent landscape – this was before I knew about Reaper, and looking back now I know that it would’ve been a LOT easier to have all the same. Is there a way to modify the code to fit all the videos properly without cutting off any of the video? The code that I used now cuts off heads and instruments – a totally horrible business!

    I looked through your videos, but maybe I missed something? Is there a way to modify how the frames are placed, or even to dictate placement yourself? If not, should I rather try to convert the odd ones out (at this point it seems to be a few landscape ones), and then try again with that? I’m totally useless with codes too – tried to look through, but it’s all Greek to me…

    I hope this reaches you, and that you might have some advice for me – it would certainly be much appreciated! Have subscribed to your channel and look forward to going through all your videos when I have a bit more time!

    Kind regards,

    Heinrich Lategan

    • Hi Heinrich, I’m pleased to have answered your question within facebook but I thought I would copy my answers here for people to see:
      The easiest thing is to download the latest version of the code and set the Landscape/Sq/Portrait to the middle setting (Square video cropped from landscape or portrait). That is less likely to crop too much from portrait or landscape. This can be downloaded from
      If you need to change the zoom or position of a video go to the problem track and use FX>Video Processor>opacity/zoom/pan just on that track. There’s a guide to zooming and positioning videos that are wrongly sized or off centre at:

  2. Jak352, this is really great. Didn’t know you already had so many features added to your script. Many thanks for the video and the script. This is a new level in Reaper video editing. Greetings Eli

  3. Hi Jonathan!
    Thanks for the video preset on Reaper. Is it possible to set the “Lead Track Number” higher than 10?
    I have other 18 tracks left…

    • Thanks for the quetsion. Yes, you can edit the code in the “Combine: Grid of videos” preset to change the numbers in the code to allow this. Change:
      //@param 1:boss “Lead Track Number” 2 2 10 6 1
      to say
      //@param 1:boss “Lead Track Number” 2 2 20 10 1
      and then it’ll allow you to go up to 20 for instance. Then save using ctrl S on pc or cmd S on Mac.

  4. Thanks for this, really helpful! I am doing a landscape matrix with a few portrait videos. Most of them are squashing into a landscape box, but there are a couple that are just too zoomed in already. They have black on the sides of the picture but I would rather have a coloured background. How do I remove the black on the sides? I have both the “automatically resize” tick boxes unchecked in project settings.

    Also, I am getting duplicates of the lowest track number video, even with the “duplicate lead video” option turned off. I have also had triplicates and quadruplicates when tracks with video elsewhere are unmuted. eventually I would like them unmuted! any suggestions?

  5. Hi Jonathan,

    Your “Combine: Grid of videos” preset and Reaper advice has been so invaluable during lockdown (and beyond). Thanks so much!

    As a music teacher, I’m currently putting together a virtual school orchestra. All the children have been filmed in portrait but I was wondering how I could change the number of columns and rows. For example, I currently have 3 rows of 4 videos, and a final row of 3. This seems a little clunky design wise, when 3 rows of 5 videos would mean there’s no empty space at the bottom. I’m sure it’s an easy fix, but I’ve haven’t been able to work it out so far. Any help would be gratefully appreciated.

    Many thanks,

    • Hi Jude, Thanks for the message. The easiest way of getting 3 rows of 5 videos is to use the “Combine: Grid of Videos” preset in the Video Processor plugin in Reaper and switch the Landscape/Sq/Portrait rotary control to the vertical central position (Sq) as this will allow Reaper to crop the videos to the relatively square shape required to get the portrait mode videos to fit pertfectly into the grid shape you suggest. This requires the Stretch/Crop/Full rotary control to be in the vertical (crop) position. Does this help?


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