Here in the snowy early days of 2009, I am setting my metronome and practicing fingering studies on my beautiful new guitar.

Every few days or so I find I can bump the tempo up a notch, getting a satisfying confirmation of my improvement; and then I will allow myself to plug in to Guitar Rig and lay down some punishing heavy metal nonsense. All told, it’s much more fun than playing a videogame.

Knowing this, friends often ask me what I think about Guitar Hero and Rock Band. Well, from a few casual plays, I have developed no interest in learning to play an oversimplified imitation of my axe. But for a musician to express contempt towards the game, and insist that Guitar Hero fans should dump it and go learn to play a real guitar, would be a harshly purist view of how one should spend one’s dwindling stock of hours on Earth.

It would also be a little like saying to a Tomb Raider fan: “Why don’t you just go outside and climb some rocks and shoot some bears for real?” Sure, it would be more challenging, and maybe even more fun, but the game is not intended as a perfect simulation of the real thing.

On the other hand, these games do inevitably represent ‘playing’ music as robotic, supervised work. Despite the limited space made for ‘improvisation’ in such games of late, most of the time you are required to do exactly what is preprogrammed into the game. There is no room to drag the tempo a bit in the verse, or to suddenly make up a cute lead harmony in the chorus.

Essentially you are trained into a Pavlovian response to a series of Quick Time Events, the reward for which is that you get to hear a prerecorded song the way it should be. One of the great pleasures of playing music for real, though, is doing it your own way: making innumerable micro-decisions about timing and phrasing that add up to an interpretation.

But the stern box-like structures that music games force the player into make this difficult. I was reminded of this in another way recently when duetting on Aha’s Take On Me with Lips developer Keiichi Yano (who, luckily for me, has a beautiful falsetto) on stage in a futuristic Zürich cyber-mall.

Lips tries to carve out opportunities for player expression by encouraging you to pose or use the mic as a tambourine, but its scoring system, as in all karaoke games, is still pedantically rigid.

Part of the fun of real karaoke is singing a familiar song in an unexpected way, but that’s something a videogame system doesn’t know how to evaluate.

In general this is part of a larger conversation about the extent to which a videogame allows you to ‘play with style’. The best videogames, I propose, have a certain excess of potential built into their control system that allows the player to show off while accomplishing the preset tasks. The game doesn’t just give you the tools to do the job; it gives you tools that are flexible enough to do the job in different ways.

This is as true of Defender as it is of GTAIV, or as it was of a certain epoch in the development of Tomb Raider, where one could somersault and backflip at will. (The increased fluidity of movement in Underworld, unfortunately, has come at the expense of some of this freedom.)

Real musical instruments, of course, also boast extremely deep interfaces that have been honed over centuries to allow for expressive nuance. In Guitar Hero or Rock Band, by contrast, it is an understandable disappointment that you are not allowed to free solo over your favourite Aerosmith or Sabbath track: the interface simply wouldn’t be up to the job.

And yet, practicing to the rigid structures of Guitar Hero, like playing dry studies along to a metronome, is at least likely to improve your command of rhythm. And, looking away from that depressing plastic nullification of the beautiful complexity of a real guitar, I find myself rather tempted by those drum controllers.

Playing the drums in Rock Band or World Tour is far closer to actually playing the drums. That skill is transferable to a real set of Ludwigs and Zildjians in a way that facility with the plastic ‘guitar’ obviously isn’t.

Maybe, after all, we can hope for the best of both worlds. According to a survey by UK music charity Youth Music released at the end of last year, of the six million young people who play music videogames, nearly half of them have been inspired to take up a real instrument. If Guitar Hero becomes a gateway drug to a lifelong addiction to Les Pauls or Stratocasters, then everyone can be happy (even if they don’t work for Gibson or Fender).

I’ve been playing guitar, on and off, for 20 years, which is a lot longer than I ever expect to be interested in any single videogame. Games are for Christmas, but a musical instrument is for life.