You are an aspiring singer/songwriter and while surfing the internet, you come across the sheet music for a song you think will display your talents well. You don't see any notice of copyright on the webpage or the sheet music. You notice the songwriter's name and after doing some internet research determine that he has been dead for some 22 years. You decide to record a video of you singing the song, and you post it to a YouTube-like internet site. A few weeks later, you receive an email from an attorney informing you that you are in violation of copyright law, and if you do not immediately take down the video, the songwriter's estate will pursue legal remedies. What do you think? Did I do anything wrong? Are you in violation of copyright law? Explain.