Is the fact that I kind find most copyrighted sheet music online for free just a lack of copyright law enforcement?

No, it's not a lack of copyright law enforcement. While copyright law does protect sheet music, the internet makes it easy for people to share copyrighted material without permission. This can be done through websites, file-sharing networks, and other online platforms.

While there are laws in place to prevent copyright infringement, it can be difficult to enforce them. This is because the internet is a global network, and it can be difficult to track down people who are sharing copyrighted material. Additionally, many countries have different copyright laws, which can make it difficult to prosecute people who are infringing on copyright.

As a result, it is relatively easy to find copyrighted sheet music online for free. However, this does not mean that it is legal to do so. Copyright infringement is a serious offense, and it can have legal consequences.