Music is a practical subject. It has the power to change people's lives. It also has the power to change the literacy and numeracy scores of whole schools! Music teachers need to stop being warm and fuzzy about the subject for which they have a great passion. Music teachers need to learn to speak "Admin" and stop expecting administrators to speak "Music". We all know that music is worth studying per se and should be at the core of every curriculum, but it will only happen if we use every trick in the book and every piece of research available to convince others of the non-musical and measurable (side-)effects of music. We are in a climate of "If it can't be measured, it doesn't get funded". Let your administrators know what the measurable effects of a strong music performance program are.
The following is a list of advocacy sites that you can use to extract powerful arguments to defend your programs. I hope they help. Many of these links have further links to other links, if you know what I mean. You could be here for hours! If you know of sites that are not listed here, let me know so I can add links to them. If you find that any of the listed sites are dead, let me know that too!
Keep up the good fight!
The Music Council of Australia
Australian Music Association
USA - National Association for Music Education
USA - Music Education Online Organisation