Spányi has won first prize at international harpsichord competitions in Nantes (1984) and Paris (1987). He has given concerts in most European countries as a soloist on five historical keyboard instruments (organ, harpsichord, fortepiano, clavichord, tangent piano) as well as playing continuo with various chamber  music groups and orchestras. He has been artistic director of the Hungarian baroque orchestra Concerto Armonico since its foundation in 1983. He has recorded an extensive discography for different labels as a soloist and with orchestra. Between 2006-9 Miklós Spányi was artistic director of the Finnish early music group
Ensemble OpusX and he is currently associate advisor of the ensemble.

For some years Miklós Spányi's work as a performer and researcher has been focused on the oeuvre of Carl Philipp Emanuel Bach. Today he is one of the world’s most acknowledged C.P.E.Bach scholars and performers. For the Swedish label BIS he has been recording C.P.E.Bach’s Complete Keyboard Concertos as well as his Complete Solo Keyboard Music, of both series numerous cd's have already been issued. Hungaroton Records has launched the series Tangent Piano Collection with Miklós Spányi, mostly featuring chamber music with tangent piano. For Könemann Music Budapest Miklós Spányi has editied some volumes of C.P.E.Bach’s solo keyboard works. He has also worked intensively to revive C.P.E. Bach's favourite keyboard instrument, the clavichord. Miklós Spányi has been teaching at the Oulu Conservatoire and the Sibelius Academy in Finland since 1990. Currently he is also associated as teacher with the Staatliche Hochschule für Musik und Darstellende Kunst in Mannheim, Germany, and with the Liszt Academy of Music in Budapest, Hungary. He has given  masterclasses in the Netherlands, Belgium,  Germany, Switzerland, France, Portugal, Hungary and Finland.

Miklós Spányi is also appreciated as improviser and composer.