I'M PLAYING in a band for the local production of Me And My Girl. It's pretty challenging for me, and requires serious practice. The trouble is: when? Although certain friends are convinced that home workers loll on the sofa all day, picking their feet and flicking idly through magazines, my brain's guilt centre wouldn't allow it. Work time is for working, not blaring out The Lambeth Walk. Practising my sax part is also verboten while daughter is playing piano, or when anyone is on the phone or trying to watch TV. I played in a show band during my late teens, and can't recall any rules or regulations. Shared houses were so chaotic that no-one registered endless renditions of I'm Gonna Wash That Man Right Outta My Hair. These days, my windows of opportunity are distinctly limited.

Late at night is an option, but only if I'm willing to wake up my children and have them collapse with exhaustion at school. We spent years trying to coax our offspring into respectable sleeping patterns. We hovered over their beds, murmuring soft goodnights, knowing full well that a furious howl would pierce the air the moment we crept towards the door. Finally, in desperation, we resorted to the "controlled crying" technique, although there was no "controlled" about it. Basically, you leave your child to cry at night until the only thing for it is to stuff your pillow corners into your ears, or stagger down to the kitchen for gin. It's horrendous, but it worked. I'm not prepared to ruin everything by honking out Leaning On A Lamppost at 12.30am. Although I could do it on the corner of the street ...

Practising after school, when the kids are around, is the obvious solution. However, playing an instrument has a similar effect to trying to conduct a phone call. The moment you begin, your children start needing things. Urgent questions are pinged at you. Scrawled notes which read "CAN I GO ON COMPUTER???" are thrust under your nose. Plus, I fear that the kids will report to their teachers that they are no longer fed or given clean clothes as their mother is too wrapped up in frantic songs which lurch from key to key and make her swear a lot.

Someone lends me a CD of the show. This is more like it. I'm hoping that, if I play it often enough, the songs will seep into my brain by some process of osmosis. That way, I'll learn them without actually having to do anything. Life will continue as normal - just with The Sun Has Got His Hat On playing full-blast on a loop.

Surely my family can tolerate that? I tried to brush up my appalling French in this manner, after a bilingual friend insisted that: "All you need to do is listen to French radio or language CDs as often as you can. You'll be fluent in no time."

It didn't work. I still spent most of last summer's holiday grinning inanely when our cottage's owner popped by for a chat. When he explained that Gaston, his beloved old dog, had passed away, I made the grave mistake of looking delighted.

It reminded me of travelling by train with an old boyfriend. We fell into conversation with the man opposite who, in a broad Yorkshire accent, told us a long and very convoluted anecdote. Finally, he finished his story, and my boyfriend burst into appreciative laughter. "It wasn't funny," the man growled. "She was burnt from head to foot."

On a happier note, the Me And My Girl CD seems to be working. I have started to hum the overture while queuing in shops. One night, I dream the tap-dance sequence. The show has pervaded our home to such an extent that my sons now spend great swathes of time in their bedroom with the door firmly shut. J, too, has relocated to his workroom "to study".

I hardly see anyone, and it's rather lonesome around here, but at least the songs are now firmly embedded in my brain.

Trouble is, will I ever be able to get them out?

*Fiona's new novel, Mummy Said The F-word, is out now (Hodder, £12.99)