So, i've finally got some hands on time with Wii Music today, but I was not the first one to get their "hands on" it. I made my mom have the honour of being the first to play the game, with me and dad watching as she played 
The game started with no menu's, it had the tutor appear, and teach the basic 4 ways of operating the instruments in the game. My mom did all the tutorials and then played her first song! The rhythm of "twinkle twinkle" is well known to my mom (she is the one who taught me that afterall ) She did pretty good in her first ever try at playing instruments using the wii mote (she used to play real instruments back in her days). How did it go? well here is a Video 
After that..mom and dad, went on playing for hours and had real fun making music and seeing their music being played on the BG, as they played the different instruments. (your previous plays add to the whole arrangement, automatically) soon they had done a whole 2x3 person band music of DoReMe (another one my mom and dad know, thanks to "The Sound of Music" ) well, it was good but not... how do I say this... video worthy However the amount of happiness and joy my parents had , was more than worth it to give it a 100 popularity points
Later I sat and experimented with a few things, wanted to see if I could do some custom changes to songs I know. I actually wanted to play the SMB 1-1 song.. so to unlock it, went on playing, soon I unlocked 47 songs but SMB song was no where to be found 
One thing Wii Music really helped me in was, knowing the names of all those songs that I liked but never knew the names of. You know, the songs that came in Tom and jerry cartoons and some other merry melodies or Silly symphonies.
Here is a video of me doing that song which comes in that Tom and Jerry episode, you know, the one where nibbler sings the Ferero Rocher song
and here is another video of me playing a song thats OUT of this WORLD, and I think I heard this in another Tom and jerry episode.. I used this instrument I like very much, whose name I never knew till I played the game, and also dont know now, only remember that it starts with a "D" hehe.
Youtube HQ Link is be HERE is
You wont know the difference unless you've heard the original, tell me how it was I know I am no expert and it was just my first try, wanted to see how the whole thing goes. I like the second on more!
Cant wait to sit and record some videos of me playing with some beat boxer or maybe doo wopper, but, I want my SMB 1-1 theme! Played for 5h:47m today and it was awesome, unlocked 47 songs, SMB 1-1 not included, played only 4 songs till now though
P.S : Btw, you have to hand it to the guys who do the Wii game musics, I mean, everyone of those Menu Musics are so soothing and relaxing, they are some of the best musics I have heard in recent times, the one that comes when you save a video is just too good, they are many in other Wii branded games too, and ofcource SMG also has some good music.
All in all.. I love Nintendo's music