Complex sentence: From 1984 to 1988 Holtslag taught at the Guildhall School of Music in London, in 1988 appointed a professor in the Royal Academy of Music in London and Hochschule für Musik und Theater Hamburg.
Split into simpler sentences: From 1984 to 1988 Holtslag taught at the Guildhall School of Music in London. In 1988 he was appointed a professor both at the Royal Academy of Music in London and the Hochschule für Musik und Theater Hamburg.