In addition to hundreds of private clients, Spiro also tunes for various institutions including:
- The Ritz (London)
- Caledonian Club (Mayfair)
- Clarendon Hotel (Blackheath)
- George Abbot School (Guildford)
- Halstead Prep School (Woking)
- Royal Holloway, London University (Egham)
- Sir William Perkins (Chertsey)
- Woking College (Woking)
and some notable individuals including:
- Nicky Spence – Principal, Royal Opera House
- Paul Weller – Singer-Songwriter and Musician
- Thomas van Heel – Keyboardist to Paul Weller
- Aidan Oliver – Chorus Director, Glyndebourne Opera
- Gavin Greenaway – Emmy award winning pianist, composer & conductor
- Rachel Parris & Marcus Brigstocke – Comedians