He almost singlehandly established in his country both the balletic genre – with Mīlas uzvara (‘Love's Victory’, 1934) – and the operatic with Uguns un nakts (‘Fire and Night’, 1913—19) and Dievi un cilvēki (‘Gods and People’, 1921).

Jānis Mediņš's memoir Toņi un pustoņi (‘Tones and Semitones’, published in Stockholm in 1964), provides posterity with many details of his early years.

He wrote his first composition aged 11, called Sudmaliņas (‘Windmill’) for piano, but many early pieces were lost due to his mother's habit of using paper lying around the house to wrap up herrings brought from the market.

The Māmuļā Association had been founded in Riga in 1904 and both Jānis and Jāzeps soon started playing in their theatre orchestra, the Fischer Kappella.

The society's theatre was destroyed by fire 1907 and relocated to the Interimteatrī, where they played Jāzeps Vītols's music for Aspazija’s drama Vaidelote.

Managing to avoid army call up, from 1909 Jānis took various odd jobs around Riga (including working in a piano shop, in orchestras and making recordings of Latvian art music and folksongs).

He first conducted when taking part in another amateur orchestra, this time made up from mostly factory workers from the island Sarkandaugava on the outskirts of Riga.

The next time was in the Latvian Opera: Jurjāns had noticed his ability when standing in as chorus-master, and suggested he conduct performances of works already in the repertoire (Life for the Tsar and The Demon).

[1] Actor and director Jēkabs Duburs heard these extracts, and with fellow-businessmen sponsored Jānis to give up his orchestral position in order to continue work on the opera.

Jānis took his family abroad, spending time in Rostock, Lübeck and Berlin and then, from 1946, living in the Blomberg refugee camp in Germany with many other Latvians.