I took Current Squeeze to see Sweeney Todd at the RFH on Saturday night. One of my favourite musicals this - I played the Judge once (only a little bit better than great West End hero Philip Quast did in this production - well done to him!) and know all the words. I spent a lot of it watching with my mouth wide open as my tongue moved with the lyrics. Most unattractive, plus Squeezecliffe accused me of gawping at the juvenile lead. (Not a phrase for these pedo-conscious times is it, 'juvenile lead'? Must take care not to use it on a public bus.)

A lot of the comment about this concert performance concentrated on the fact that great Welsh Bryn Terfel was singing the title role alongside mere 'musical theatre' actors in the other parts. There's a rather unpleasant and, in my view, wrong blog on the Guardian website, which compares the singing of the various performers. I was hardly struck by the singing - the main part of Todd feels right sung by a guy with a massive foreboding, operatic baritone (albeit unpleasantly miked), the rest are fine done by less awesome voices. What hit me was the difference in the acting. Terfel is magnificent on an operatic stage - recent performances at the ROH have included an awesome third act of the Valkyrie when, barely able to sing, he managed a majestically pitiful performance through body language alone, plus a beautifully wicked Gianni Schicchi.

On Saturday, he looked a little lost. He hammed it up a lot, barely engaged with the detail of his songs and often seemed to be trying too hard to remember his words (which you can't fault him for in the infuriatingly clever-clever 'try a little priest' song - one of the show's most famous numbers, and its worst.) He seemed on a different plane (and not a qualitative one) to Maria Friedman's surprisingly funny Mrs Lovatt and Daniel Evans' unsurprisingly fine Tobias. Partly justified by the part, I suppose - but you still felt Terfel could have stooped a little more for a more complete conquest.

Still, I loved the show. Occurred to me that these sort of semi-staged events are an almost ideal place to hear Sondheim. It dampens the disappointment which the faulty books and strenuous requirements of most of his musicals make likely, and also doesn't commit producers to long runs. Let's have the complete semi-staged Sondheim some time soon, RFH! If you can hear me. You probably can't.