I have bipolar, and as such, suffer from certain obsessional behaviour problems. These range from checking my emails twenty times an hour, to how I organise my music.

The way I listen to music has changed with the times, and my methods of classification have also changed. Where once all my music was filed alphabetically on records, tapes and cds, it is now all in folders on my iPod. I can listen to, and amass, seemingly unlimited amounts of music. Equally, there seem to be endless options as to how I can arrange said music.

However, on examination, my methods have remained similar. I used to make mixed tapes - spend hours hunting for, and selecting perfect tracks. The inspiration generally came from having listened to enough new good music that I was no longer happy with the old tapes.

Making a tape was always a precise and time consuming operation. Working out what would fit into ninety minutes, making sure there were no gaps, no jerky starts, rewinding and checking. And I had endless rules. For example, I wouldn't put two tracks by the same artist on the same side, the best tracks had to be balanced out through both sides, and it was not acceptable to have a track run out on the end of the side.

Now I am part of the iPod generation, I have playlists. Gone are the days of precision and commitment. On an iPod, any decision can be reversed, tracks can be added pretty much instantaneously, and the only time limit is the memory of the Ipod (which is no comparison with a ninety minute tape).

But, I still have my rules. I still make a new playlist when I have a glut of new music. The only difference now is I have one overall playlist which everything gets added to. I don't delete my playlists. The same way I have kept all my mixed tapes, my playlists are soundtracks to certain periods of my life. I also don't delete tracks from my lists. Once it has been committed, it stays. In the same way with every mixed tape I made, there was one annoying track which I always wished I'd never added, the same is true of my playlists. Whilst there is no logic to not deleting the offending track on my iPod, I never do.

However, because of the speed of making lists, there are now so many possibilities. I can make a list for every mood, for every eventuality. Sometimes, I feel overwhelmed by the range of options and sit in front of the computer, motionless, lost in thought over the next best way to tackle the classification of my music..