myself personally I dont touch anything unless people say if i can use it for non commercial use or commercial use. In your case since I know you I would send you a mail but for the passer by I would probably just not touch it. The reason being well one thing is I dont know what your plans in the future are for the music eg: do you intend to pass it through itunes etc etc in which case will youtube get mad at me one day lol. So for me I would also say about if it can be used for commercial reuse or not. the easiest way is to link a creative commons license that is what I do that way everyone is clear since your giving it away free its usually the easiest way to deal with it. For the most part I would pass over yours and anyone else who just asked to be given credit and didnt say how it can be used. Eg half the time I remix stuff or use only a portion . If I want to say sell it in a video on a dvd or put it as part of another free thing is that okay. Like say an intro or outro.
so when I look at stuff I look at the following and so do most
1) can i use only part of it or chop it up and add more to it?
2) can use it in some commercial work or no?
for me if i like the music i dont worry about commercial i just remember but i do chop stuff up often hehe