In 1955 Frankel succeeded Edward Clark as Chairman of the ISCM. That year issues arose about certain expenses Clark had claimed while he was chairman. Clark alleged that Frankel had accused him of fraud. Frankel denied he had ever made such a claim, but nevertheless said that such a claim, had he made it, would have been true. This amounted to slander as far as Clark was concerned, and he sued Frankel in the High Court. While Frankel's alleged slander itself was unproven, the jury exonerated Clark of any wrongdoing and he felt this meant his integrity was intact. Clark's wife Elisabeth Lutyens ever after referred to Frankel as "composer and ex-colleague".