Another PITA with chrome is the spell check which questions everything even when it is correct.

may be because it uses American spelling and not UK English

Yes, that's correct. i will attempt to change it one day although I have heard that is a pain in itself.

I find myself constantly Googling words that I know how to spell.

Not that difficult to change:
Settings:
Advanced settings:
Scroll to Language and then you have to actually add English (United Kingdom) to the list.

I'm trying to listen to some recordings on a website and get the following message:

rt05-1ss1
This plug in is not supported.
followed by rt05-15st1.........then rt05-16te1


So I followed instructions and installed the latest Adobe Flash Player;
Cleared the browsing data (which is causing me some grief)
All these problems are only when using Chrome, so can someone please tell me how do I install a new browser?

Is it a public and safe site (not private to you, family or friends)? If so, maybe you could post the URL for others to try it in various browsers.

Brief audio samples of the first three training levels for both the technologies are provided in the Samples section. Works available in VS technology can be listened to and/or downloaded from the VS catalogue page. To use these training aids you need to install a specific software tool, the Myriad Music plug-in, into your web browser. Alternatively, you may download the same training aids converted already in mp3 format from the mp3 catalogue page.

The VS technology requires that you install the Myriad Music plug-in and a browser compatible with it. The Myriad Music plug-in and a version of the SeaMonkey browser that is compatible with the plug-in can be downloaded from this page. Please install the Seamonkey browser first, then the Myriad Music plug-in, and ensure that the plug-in is visible by the browser. You can use the SeaMonkey browser only for Choralia, and continue using your preferred browser for all other websites. Please use the version of SeaMonkey provided in this page, and never update it to a newer version: the newer version may not be compatible with the Myriad Music plug-in. If a newer version was installed, please re-install the version provided in this page. If any warnings related to the installation of an outdated version are displayed, ignore them and complete the installation anyway.

Myriad (the author of the plug-in) will not provide any support for the Myriad Music plug-in, which has been discontinued.

Why, but whyyyy ???

Our plug-in complied to a standard called NPAPI that used to be compatible between all browsers the last two decades.
Unfortunately, for "security reasons", NPAPI support has been or will be discontinued in all major browers. No replacement is proposed at this time.

So, what can I do ?

We worked very hard to provide an alternate way of sharing music scores on the Web, and developed a brand new HTML5 app for this, along with a dedicated data format, called Myrweb.

This format can be managed through our score editor Harmony Assistant. A Myrweb export can then be viewed, played, etc, without requiring the user to install anything on their computer, smartphone or tablet.

I am visiting a site that still uses the old Myriad plug-in

The webmaster for this site should seriously consider to switch to the myrweb system. If possible, contact them and direct them to this page, especially the section below.

I am a webmaster and I want to switch my site to the new system (Myrweb)

There are several tools and tips that can help you in this task. We are currently setting up a page to explain all this.

SeaMonkey is a free and open-source Internet suite. It is the continuation of the former Mozilla Application Suite, based on the same source code, which itself grew out of Netscape Communicator and formed the base of Netscape 6 and Netscape 7.

SeaMonkey was created in 2005 after the Mozilla Foundation decided to focus on standalone projects such as Firefox and Thunderbird. The development of SeaMonkey is community-driven, in contrast to the Mozilla Application Suite, which until its last released version (1.7.13) was governed by the Mozilla Foundation. The new project-leading group is called the SeaMonkey Council.
Compared to Firefox, the SeaMonkey web browser keeps the more traditional-looking interface of Netscape and the Mozilla Suite. Many XUL-based Firefox and Thunderbird add-ons can be modified for compatibility with SeaMonkey,although add-ons built with the WebExtensions architecture used by newer Firefox versions are not yet compatible.

This is getting to be more difficult than I thought it would be............but strangely I suspect I have the myriad music plug in - either on my old laptop or my old desktop - both of which work (kindof). If I find it, can I transfer from one computer to another by USB?

I've download Firefox onto both laptops and have a different error on each:

RT05-1te1
and
rt05-1ts1