Thanks for contributions so far. I was thinking about using the Melody/Harmony plug-in so that musical scores could be displayed on my web-site and that those viewing them would have more control over such things as viewing them, printing them out and even transposing to another key. Since my first request, the Myriad site appears to be back on-line and I have tried out a trial page. It didn't work particularly well, crashing for some reason (probably my fault). The score also appears rather small initially, though magnification is a user option. I think that my web-site would become dependent on the plug-in being available from the Myriad web-site and if it went down mine would cease to function properly. Though I will look into this further, I am inclined to 'keep it simple' when it comes to my site.
Having said all that I am delighted with the Harmony Assistant program (and Melody Assistant which I used previously), though I barely scratch the surface when it comes to using all its facilities.
Cheers,
Ian