Four years spent on the music staff at English National Opera in London provided the invaluable experience of working with all voice types in a broad range of operatic styles, but eventually he resigned in order to launch a freelance career. Invitations to perform with a wide variety of singers on the recital platform followed in quick succession. BBC studio broadcasts, recitals at the Wigmore Hall and many other engagements throughout the British Isles and across Europe soon gained for him a glowing reputation as a singers' accompanist of rare sensitivity and support.

In addition to his prolific performing activities, a deep interest in vocal technique and performance style has led to the development of an immensely successful vocal coaching practice. David's wide-reaching reputation in this field centres around a thriving London-based studio where his client list includes young aspiring professionals from all points of the globe as well as numerous prominent international artists. Many of the latter have invited him to collaborate in recital at such prestigious venues as the Edinburgh Festival (Scotland), Wexford Festival & Concert Hall/Dublin (Ireland), Roy Thompson Hall/Toronto & Centre des Arts/Montréal (Canada), La Monnaie Opera House & Palais des Arts/Brussels (Belgium), Concertgebouw/Amsterdam (Holland), Salle Gaveau & Châtelet/Paris (France), Chopin Festival/Valldemosa (Spain), Berwaldhallen & Konserthuset/Stockholm (Sweden), the Hong Kong, New Zealand, and Adelaide International Arts Festivals, Tsuda Recital Hall and Suntory Arts Centre/Tokyo & Minato Mirai Arts Centre/Yokohama (Japan), Performing Arts Centre/Seoul (Korea), and National Concert Hall/Taipei (Taiwan), to name but a few.

CD recordings include 10 Volumes in an on-going series entitled Il Salotto (The Salon) for Opera Rara London which explores the extensive but hitherto neglected repertoire of solo songs and vocal ensembles with piano accompaniment, specifically composed by such mid 19th century composers as Mercadante, Rossini, Pacini, Donizetti, Verdi, Balfe, Gabussi, Costa, Meyerbeer, Mayr etc for performance in the private salons of that era.

Also recently released by Trust Records New Zealand are Elegy. A Recital of English Song with Paul Whelan, Canciones Españolas with Deborah Wai Kapohe and Franz Liszt Songs with Keith Lewis.

Recent and forthcoming engagements encompass recitals in Brussels, London, Paris, Lille, Amsterdam, Rotterdam, Stockholm, Frankfurt, Geneva, Japan, India (Bombay), Australia (Recitals at the Australian Club & Hunters Hill Music Club, Musica Viva Tour with Barbara Bonney), New Zealand (Gisborne, Wanganui, & Tauranga Festivals), a Gala Concert at Buckingham Palace to celebrate Opera Australia's 50th Anniversary, as well as coaching commitments in Sweden, Norway, France, Germany, Japan, Singapore, Malaysia, New Zealand and a continuation of his twice-yearly Guest Coaching engagement at Opera Australia in Sydney - courtesy of the Johnson Bequest.