Television programme-makers seem to have rigid mindsets when it comes to thinking of formats. Producers usually regard celebrities as necessary to almost any programme - or alternatively ordinary people who can be fooled into thinking they may become celebrities for at least 15 minutes.

So Maestro (BBC2) had to find eight famous people for its experiment in teaching people how to conduct an orchestra. The definition of 'famous' is remarkably vague nowadays, so the 'celebrities' included the former bass player with pop group Blur (Alex James), a former soap star (Bradley Walsh), and someone called Goldie who was unknown to me but is apparently well-known in the world of 'drum and bass' (you needn't know). The winning conductor after six programmes will get the chance to conduct the orchestra at Proms in the Park. The commentary lied that all eight contestants have "a passion for classical music". Some contestants had the unfair advantage of having studied the piano or violin, while others were total novices.

The series is presented by Clive Anderson (pictured), so we know it will be lightweight and facetious. In fact, it started off by making the celebrities conduct the BBC Concert Orchestra without any prior tuition: a good chance for a laugh. Several of them couldn't understand why the orchestra was playing so slowly, not realising that they had to move their arms faster to increase the tempo. Peter Snow was rubbish at the task and eliminated in the first round. The programme made a few educative points - for instance, that conducting requires a lot of stamina.

Who Do You Think You Are? (BBC1) is another celebrity-based show, back again for its umpteenth series. This week Patsy Kensit (another soap-star) delved into her family history, seeming surprised to find that her grandfather as well as her father were criminals. But she cried copiously when she discovered some nicer people farther back among five generations of her ancestors, including some craftsmen and a clergyman. This series may interest people fascinated by family histories but I can't get very interested in my own distant ancestors, so why should I be fascinated by Patsy's, especially as she didn't even know what a curate's or a sexton's jobs entailed?

If you can't get celebrities for a TV series, you have to find eccentric members of the public to be your victims. The title of Make Me a Christian (Channel 4) reminded me irresistibly of a piece of graffiti whose punch-line is "If I gave her the wool, would your mother make me one?" This programme chose an unlikely group of guinea pigs to be converted to Christianity by the Rev George Hargreaves and his three evangelical helpers. The victims included a pole dancer and a tattooed overweight biker. They must have been odd to volunteer for the scheme in the first place.

The first programme suggested that Britain is in trouble because we don't observe "Christian Values" - an ambiguous phrase. I assume it means the spirit of how Jesus lived, but George and his chums took it to mean literal belief in the Bible. Their sanctimonious, judgemental approach was hardly likely to convert the sinners. When the burly biker challenged George to explain why the Bible is true, George simply shouted him down. When George took the participants to York Minster, he asserted "Christ is here" but a woman understandably asked: "Where is he? I can't see him."

Kevin McCloud and the Big Town Plan (Channel 4) was in the long line of TV programmes where television sends in experts to solve problems. Grand Designs man Kevin McCloud went with a team of architects to try and revitalise Castleford in Yorkshire, which has deteriorated since its five coalmines were closed. The project involves local people and has taken five years, starting with the building of an unusual new bridge over the previously polluted River Aire. It was an unusually positive and uplifting programme.