To understand what he's on about, it's important to understand how Wii Music works. As Jake explained it to me, whenever you decide to play a note, the Wii works out something that will sound okay. So if you're playing in the chord of C, and decide to throw in an extra note, it'll pick one of the notes that make up the chord (C, E or G, in this instance), and play it. That way, even if you're banging away to any old rhythm, songs might sound wonky but they'll still sound familiar.
"The problem with this is there are going to be no happy accidents, and most of music writing is happy accidents," said Jake, wearing his best composer hat. "It comes from noodling about on a keyboard and finding something that makes you go, 'Ooh, what was that?' That's never going to happen here because they're trying to make it sound nice, not like someone punching a piano. So there will be nothing new, nothing creative. It's just about doing something pretty and meaningless."
Oh dear. Perhaps, I thought, the Instrument Improv mode might cheer him up. Here, you pick an instrument and start playing whatever you like. After a little while other characters, known as Tutes, will appear on-screen and start "jamming" along with you, or so the theory goes. Surely this offers real scope for creativity?
Not really, because as we discovered, you end up following the Tutes' lead whether you want to or not. Jake tried playing a tune in 3/4 time rather than 4/4 - "Which is the timing everything in this game seems to be in" - but the Tutes just chimed in with their pre-set 4/4 pattern. Nor would they follow different tempos.
"It lets you waggle about a bit and think you're doing something by yourself. Then it just creeps in with the pre-set backing pattern and you will inevitably fall into that," said Jake. "Which is quite fun - I sort of enjoyed it, briefly. But to call it improvisation is pretty laboured. It's no better than the auto-accompaniment from a keyboard. In 1983."
It doesn't help that all the audio in Wii Music - the instruments, the backing tracks, the menu music - sounds like it is emanating from a keyboard in 1983. Clarissa agreed: "The music is really awful, and the sounds are terrible.
"I do have a personal hatred of that whole midi sound. I think timbre's a really important thing in encouraging people to like and enjoy music. The problem with this is the sound isn't nice; it's plasticky and fake, and a lot of the arrangements are really cheesy. So it doesn't inspire an appreciation of quality music."
Indeed, you can't help feeling they should have called it Wii Muzak, particularly when it comes to the horrendous renditions of classical pieces. The excerpt from Swan Lake, the on-screen text informs us, is "incredibly moving". Not when it's being played by midi castanets and accordion, it isn't.
However, reckoned Jake, the developers had little choice but to take the midi option. In a game like Guitar Hero, when you hit a note you hear a sample of recorded audio. That's quite a big chunk of data, but you either get it right or wrong. In Wii Music, many more permutations must be covered - which instrument you're playing, when you might hit a note and for how long.
"You'd need thousands of samples just for Twinkle Twinkle Little Star. Using midi data is an economic way of doing it," he said. "Bearing in mind the constraints of the disc, how much RAM there is and how much processing power the Wii has, they've probably done they best job they could." Even though it sounds rubbish? "Yes. Beethoven would kill himself. Except he couldn't hear it anyway."
So perhaps it isn't fair to criticise Wii Music for the audio quality. And besides, perhaps we're taking this all far too seriously - do kids really care about 3/4 time and proper violin sounds and musical algorithms? No, but they do care about being entertained, and they don't have the longest of attention spans.
I doubt most kids would enjoy banging away on Wii Music for longer than an hour or two. I doubt many of them would be that bothered about playing through a song six times, just to record all the parts themselves. And I seriously doubt they would want to complete all the lessons.
These are incredibly laboured. They ask you to grasp musical concepts which can be quite complex, without really explaining them. Each lesson requires you to play each part of a song, which means playing the song six times. Plus getting through the practice bit before you're allowed to play the proper song - so that's a dozen times. You can't even complete a couple of parts, then come back later to finish the lesson off; you'd have to start all over again. In other words, the lessons in Wii Music are as boring as most real music lessons.