You may also video tape your concert, clearly label and tag it as your composition with the date, then upload it to Youtube or some such which will serve as a record. You can also upload a cover page to a blog or something. All these little submissions would help to serve as proof in the event someone steals it and it is worth your time and money to go after them.
I wouldn't worry about it. 100% of everything is stolen today and it is unavoidable. You can check out sites such as MusicaNeo to self publish but, we now live in a society that thinks intellectual property is free for the taking.
I arranged a fugue on Itsy Bitsy Spider, posted it for free and got over 1,500 downloads. I then asked for a donation and received $2. I then locked the download asking for $3 and never got a hit. I then attended a Halloween organ recital and was shocked to hear my piece being played and my name was not listed in the program. A HS band director took my arrangement and arranged it for his band and again, no credit. I called him out on it and he corrected it.
I had the privilege of working with a (once) world renowned composer who opined that we should write to give it away. If our work is any good, he said fame and fortune will find us. But, it can't find us if we don't first put it out there.
So, given the choice, I'd rather give it away to 1,500 people than sell one copy. You know that the guy who purchased the copy made copies for his friends.
Watch the movie ARTIFACT (you can find it FREE in a couple hundred locations online) about the band Thirty Seconds To Mars and their battle with agents, record labels and publishers. In one of the closing scenes, Jared Leto asks a concert crowd of abut 20,000 "How many of you have our new album?" The crowd erupts. He then asks "How many of you downloaded it illegally from the internet?" They tripled in volume. In Jared's case, giving it away for free attracts paying people to his concerts.
There is a comic, whose name escapes me, who was offered a million dollars to produce an HBO special. He asked for more and they said no. So, he self published it, posted it for free and asked for a $5 donation and made five million and didn't have to share a penny.