Yes, If you make an arrangement of a song that is out of copyright ( Life of Copyright is 70 years after the composer's death), often known as a "trad" song, you can claim the copyright in that arrangement.

Once you have committed your arrangement to a material form, the copyright is automatically yours, but in order to protect it, you should register it.

You can do this by:-

1. Sending the ms. of your arrangement to yourself in a registered envelope. (Be careful not to forget that you have sent this to yourself. Opening it, thinking that the envelope may contain money or some other goodie, will invalidate the excercise and you'll have to start again).

This will confirm that on the date on which you sent the letter to yourself and thereafter, the copyright in the contents of the envelope is claimed by you.

The cost of this is the cost of the stamp, paper, time etc.

2. Lodge your ms. at your bank or solicitor and obtain a detailed and dated receipt. This will have the same effect as 1. above.

The cost is negotiable.

3. Register with Stationers' Hall.( The Worshipful Company of Stationers and Newspaper Makers) There is a standard copyright registration procedure. You are in fact recording a claim to a copyright and when I last looked, the cost was 40 pounds + VAT for an individual, 70 pounds +VAT for a Ltd. Company, and 34 pounds + VAT for a member of the MU. This may have changed by now.

The registration lasts for seven years and then should be renewed. You will have to pay the fee again.

4. Sign to a publisher and assign the copyright in your arrangement to him or her. However, be careful to take proper legal advice, from a lawyer experienced in the music business.

HOWEVER if the song is still in copyright any arrangement made of the song, without the permission (should be written)of the copyright owner( maybe the composer or maybe the publisher), will be the property of the copyright owner.

This is not to say that the arranger may not be credited as such, nor does it preclude a deal between the arranger and the copyright owner.

Hope this helps.