Copyrights and Playing In Public
General Overview / Helpful Links
While most of us just want to be able to play the harp and make beautiful music without having to think about legal technicalities, the issue of copyright is one that you really do have to consider when you play for money. The issue arises whenever you a) play music someone else wrote, and/or b) play someone else's (copyrighted) arrangement of a particular piece of music. Usually if you are playing at a public venue, the costs or fees associated with playing copyrighted music fall on the establishment (most of them have licenses or regular yearly fees that they play). However this changes if you are planning to, say, put out a CD on which you want to play music written by someone else. (See the links below for more info).
There is plenty of music out there that is considered "public territory". Many Celtic (and other folk) tunes have been around so long that no one knows who originally wrote them (generally referred to as "trad", ie. 'traditional' tunes). Also, if the person who wrote the music has been dead long enough, then their music is considered public territory (exactly how long is not always clear - in the U.S., for instance, they're right in the middle of debating this very issue - ref. the "Sonny Bono Copyright Term Extension Act" of 1998, currently being challenged). However, if a living person has copyrighted their own particular arrangement of a trad/public tune or song, then you have to consider that when performing it in public, especially if it's for profit.
Since I play primarily Celtic music on my harp, I tend to skirt around this issue by just learning the tune and chord structure and making my own arrangement of it (this includes some of the simpler classical stuff as well, such as Pachelbel's Cannon and the wedding marches). When I play with my various ensembles, we often mangle an arrangement so much (by changing the accompaniment, putting in different instruments) that we are no longer playing what was on the page (the original arrangement just ends up being a kind of guide). If you're comfortable with making your own arrangements, there are lots of "Fake Books" out there, that just list the tune and chords (you can find fakebooks on just about every style, Celtic to Country, wedding music, hymns, seasonal, you name it). If, however, you choose to follow someone else's arrangement closely, then it is customary to note this when you play, eg. by putting the composer and arranger's name in the program after the appropriate piece(s).
To take the safest route, you can ask the composer's or arranger's permission to perform the work in public. This is not always easy (or even possible), but often the arranger/composer will be so pleased that someone has bothered to ask that they will be happy to give you permission. Most people who arrange music want other people to play it; that's kind of the whole point! Normally they won't be too concerned about small local groups playing to local audiences. When it becomes a problem, is when someone may be making a large profit off of someone else's work.
You should also be aware that photocopying copyrighted music is technically illegal (unless there is a disclaimer somewhere that gives you permission to do so - this will usually be found on one of the first pages, or in the intro). Many people photocopy music due to lack of funds (buying real music can be very expensive for a struggling musician), music they would pay for if they could. This has led to a kind of tolerance regarding photocopies that is not reflected in the legal system (of Canada or the USA, I'm not as familiar with other countries). Also keep in mind that somewhere out there are composers and arrangers who are just as much struggling musicians as you are, and if you photocopy their stuff, they don't get paid, and it makes it harder for them to make an honest living. This said, the above still applies - most arrangers won't loose any sleep if you're just copying some music to play with friends, just remember to always acknowledge the proper sources, as a common courtesy if nothing else.
Most importantly, listen to your own conscience - few composers or arrangers would expect people to doggedly stick to the letter of the law every waking moment. Consider if the situation is hurting anyone, or not giving someone due credit, or if you are making profit off of someone else's labour. It may be a cliché, but if you can make it into a "win-win" situation, then everyone's happy, and no one has to go to court!