Comprovisador.client is the application that receives the score, which is algorithmically generated by the Comprovisador system’s host, and displays it so that the musicians in the ensemble can sight-read it during a performance. Each client computer may serve two musicians, depending on their instruments. Its Practice Mode may be used as a tool for sight-reading skills improvement.

Instructions for download:

The Comprovisador.client application runs in the Max 7 environment and uses elements from the Bach library.

  • If you aren’t a Max 7 user, please install it first from the Cycling ’74 website;
  • After installing Max 7, launch it once and then close it; If you go to your Documents folder now, you’ll notice a “Max 7” folder there;
  • To install the latest version of the Bach library (, you’ll need to go to their website and download the “Bleeding Edge Version” ;
  • Extract the “” file (extract all);
  • Copy the “bach” folder inside the “Packages” folder in your “Max 7” folder; The “Packages” folder is under “Documents > Max 7” ;
  • Now, you can download Comprovisador.client and run it. It’s free!

To find out more about the Bach Project, visit their website.

Note: you don’t need to buy Max 7 nor activate the trial mode in order to run Comprovisador.client. Also, the Bach library is free. Please, note also that the Bleeding Edge Version ( is not currently accessible via Max’s Package Manager, hence, you have to manually install it as explained above.

Known issues with Antivirus software: Some antivirus programs – namely, Avira and Avast – identify Max 7 as being infected. This is a false positive and has been duly reported. If you use one of these antivirus programs, deactivate it prior to installing or running Max 7.


If you only intend to use the Comprovisador.client application as a tool for sight-reading skills improvement (Practice Mode), you don’t need to continue reading this section.

However, if you are planning on using the application in a Comprovisation performance, it’s necessary that:

  • your computer supports Java; and
  • your computer’s Firewall allows Max 7 to communicate on all types of network.

Regarding Java, if your computer doesn’t support it, you’ll see an error message with a link to Java’s manual download page. You should install the appropriate version for your system and your Max 7 installation:

  • in Windows – if you have installed the 64 bit version of Max 7, install the 64 bit (offline) version of Java. Otherwise, install the 32 bit version;
  • in Mac – if you run Max 7 in 32 bit mode, you should install Java 6 “Legacy”. If you wish to run Max 7 in 64 bit mode so that it can use Java 8, find Max 7 in your Applications folder, right-click (ctrl-click) it, choose Get Info and uncheck “Open in 32-bit mode” from the Info window.


Regarding network access, every time a Firewall dialog box pops up, you’ll need to allow access in both network types (private and public – tick both options).


Furthermore, in Windows, certain antivirus programs may be authorised to control your computer’s Firewall, overriding your definitions. If that’s the case, it may be necessary to go to your antivirus definitions and temporarily turn off the Firewall in order to use Comprovisador.client during a performance.

Other error messages: Apart from the Java error message, another message may occur: “Error: IP not found”. In reality, this may be a good sign for it means Java is working properly! Only the server’s IP address (“”, in a performance context) hasn’t been found – which may be an expected situation.


Minimum system requirements: To be suitable for performance with the Comprovisador, your computer should have a 64 bit processor (i7 recommended) and a 13’’ display (15’’ recommended) and should run up-to-date Mac or Windows operating systems (64 bit). Preferably, it should have a dedicated graphics card (1GB VRAM or better).

And don’t forget to use the Practice Mode daily!

Comprovisador – About