Yes yes yes.
You have done what many newgrounders here cannot achieve throughout their games: you have created a game that could surpass many videogames on the PS3, X-Box, and definitely Wii (well...there's an exception on Brawl, I guess). The game itself is a fucking awesome concept. It helps fellow NGers and many other people create their own songs without having the buy a program to make it (of course, this is sort of limited, so don't press your luck if you're reading my review).
Well, yes, this is a very great game, but I'm still having trouble with how much effort could've been put into the artwork although it is at random. I know that the artwork isn't much of a matter here considering it's a music-making game, after all. But it is sort of....crucial, I guess in a good game, no matter what the entire idea of the game should be. So, you just lost one star on that, and that isn't much of a difference there.
I liked how you could actually print out the music that people make and let them see if they can actually play the music. Half of the songs I made I can't even play on drums or bass. Haha, I guess that just goes to show that I need to practice a lot more if I really want to do this.
Well, to be perfectly honest with you (and I know all you people out there who are READING this review besides the creator will most likely rate it useless), I just wish there was more options besides what you gave out. Like, you get to choose what instruments go into that band of 4, and I don't really have any complaint over how much musical quality you put into this.
I'm really glad that there's game like this out there. It'll help most of us musicians and just many other people who need a hobby. Thanks for bring this lovely piece of work to us!
Overall: 8/10, 4/5.