Orchestra la scintilla zurich/bartoli, Barbican, London

Welcome to the Cecilia Bartoli/Maria Malibran roadshow the exhibition, the album, the concerts. It's no surprise that Bartoli identifies so closely with Malibran, the 19th-century Spanish operatic superstar whose memorabilia she has been collecting so avidly for many years now. Bartoli is a kind of Malibran.

Her style is friendlier than one imagines was the case with 19th-century divas, but she has the charisma, the platform manner, the facial expressions and the old-fashioned gestures. And on this occasion, she had the frock the kind you might wear for the final of "Strictly Coloratura". They'd even erected a little platform centre-stage where the conductor would usually stand. Just as well the Orchestra La Scintilla of Zurich Opera, who started the evening sounding like pitch was negotiable, worked without a conductor. The stage was all Bartoli's.

Of course, we cannot really know how Malibran sounded whether she had as small a voice as Bartoli, whether she was prone to the same bad vocal habits, whether she swallowed the sound and aspirated the coloratura (singing or gargling?) as Bartoli is wont to do. In the end, it hardly matters. The point about Bartoli is not the voice but the artistry, and it is possible to get past the strange, at times even grotesque, vocal tics, and share in the sheer relish she has for the repertoire she chooses to sing. She's a born communicator, audiences love her, and she inhabits her texts, however rudimentary their dramatic content might be.

In the "Romanza" from Giuseppe Persiani's Ines de Castro, one of several Malibran rarities she trotted out for us, she took her cue from the long solo-cello aria and spun her line on a mere thread of sound, enticing with the melting portamenti to a single purpose rapture. And in Mendelssohn's Scena and Aria "Infelice", her alliance with the concertmaster Ada Pesch was expressively akin to making intimate chamber music together.

It is extraordinary how a singer with comparatively so little voice can communicate such big emotions. In Angelina's "Rondo" finale from Rossini's La Cenerentola, the contrast with Magdalena Kozena at the Royal Opera only a few days ago was immense. Bartoli doesn't have Kozena's voice or technical "correctness" in the pyrotechnics, but she has a big heart and the joy she conveyed put us right there in the palace for Cinderella's defining moment.

And so the evening spiralled into a kind of operatic burlesque. A Tyrolean yodelling song by Hummel suggested that we might get "The Lonely Goatherd" as an encore. Instead, Bartoli gave us her bizarre impersonation of a military drummer, "Rataplan", before fielding her very own flamenco backing group for a number from an opera by Malibran's father. I didn't stay for the animal act.