The v6 is actually a standalone Tamagotchi called the Tamagotchi Music Star, though some people still like calling it a v6. I don't have one yet, but I'll tell you what I've heard about it.
The Music Star is all about raising your Tamagotchi to become a musician. When it grows up, it will go to school and form a band with two other Tamagotchi. When your Tamagotchi is an adult and their band manages to become professional, your Tamagotchi band can perform in concerts and make lots of Gotchi Points. When they're not performing, they can also work part-time to get extra Gotchi Points.
The Music Star has a skill points system, like the v4's. This Tamagotchi has Tone, Rhythm and Originality points, which I think may determine how well your Tamagotchi does in its concerts and possibly what characters your Tamagotchi evolves in to. (I don't know that for sure though.) Your Tamagotchi also has a favourite genre of music, depending on what kind of instruments you give it, but sometimes your Tamagotchi's favourite genre may change overnight.
You can pause this Tamagotchi very easily by simply holding down A and B simultaneously, like on the v2-v4.5. Another thing that I feel like mentioning is that you can give your Tamagotchi a longer name (up to 8 letters long, instead of 5). Another thing which probably hinders you more than helps you is that you no longer earn Gotchi Points from the games. Instead, you get a daily allowance and when your Tamagotchi is grown up, as I said earlier, it can perform or work part-time to earn Gotchi Points.
Your Tamagotchi can also get stressed. When it's too stressed, it may refuse to listen to your commands, in which case you have to give it a time out. To stop it from being so stressed, you can let it play with its favourite toy (doing this lowers its musical skills) or I've heard you can also play games to help your Tamagotchi become less stressed. Your Tamagotchi can also practise to get better at music, however, this can will your Tamagotchi more stressed. (I don't understand. I can play River Flows in You all day long on my piano and it won't stress me out a bit. Actually, it'll probably make me more relaxed. I love that piece of music.)