Very few doubt that Sarah Vaughan had one of the most amazing voices in jazz — Gunther Schuller famously described her as, ‘the greatest vocal artist of our century’. Her range, technique and tone, from a cavernous baritone to a voix céleste, saw to that. But there were times, especially in the later part of her career, when this remarkable instrument was used as an end in itself, where she got more into her voice than she did her material. Songs could be overwhelmed by rococo ornamentation, and ballads so stuffed with vocal gymnastics they began to lose their meaning.

In a discography that betrays no single, exclusive commitment to jazz – for example, at her peak, Columbia, Mercury and Roulette aimed her firmly at the hit parade, where she duly obliged with hits like ‘Whatever Lola Wants’ (which reached number six in the charts), ‘Mr. Wonderful’, ‘The Banana Boat Song,’ ‘Passing Strangers’ (with Billy Eckstine), ‘Serenata’ and her biggest selling hit of all, ‘Broken Hearted Melody. Her-out-and-out jazz albums (with piano, bass and drums) often promised more than they delivered, for example, At Mr Kelly's may have been live, but the producer wanted new material so she was singing from sheet music.

There is one album, however, that captures her at her finest, and this is it, recorded live in front of a large, enthusiastic Danish audience when she was at her peak aged 39. She and her trio were part of an extensive tour through Europe where she opened nightly for the Count Basie band. By all accounts, friendly rivalry between the two meant Ms Vaughan was intent on showing the Basie band how to swing. She was in the form of her life – slim and strikingly beautiful, she adopted ‘I Feel Pretty’ as her theme but that's where the lightheartedness ended; songs like ‘Sometimes I'm Happy, ‘I Cried for You’, ‘All of Me’ and ‘What Is This Thing Called Love’ are exemplars of jazz singing at its finest. And boy, did she swing. With most jazz singers, scat singing can come close to a crime against humanity, but here, with ‘Sassy's Blues’, the instrumentally inspired invention of her scat (she was an excellent pianist) marks this performance as a benchmark of the genre. Her ballads – ‘Lover Man’, ‘Poor Butterfly’, ‘Tenderly’ – are not overwrought, but thoughtfully and emotionally delivered. No wonder top jazz musicians of the time held her in such high regard.

Find It: Internet traders, for example eBay, ask anything from £12 to £95 for the vinyl, but highly recommended is the 1987 Japanese CD release which includes an extra CD of previously unissued material from the same concert – it will take some hunting down, but it's worth it.