Besides the concerts in England being organised by Speyer, Debussy now also had to prepare the score of La mer for a performance which Édouard Colonne was planning for 12 January 1908. Colonne's familiarity with Emma, dating from her early days in Paris when she had lessons with his wife, was evident in a letter he addressed to her on 31 December 1907, which began ‘Bien chère amie’. He was planning to conduct the work himself, and asked Emma to arrange a long session for him with Debussy. By the time he finished this note, it was quarter past midnight – the New Year – and he ended it with the warm greeting to the whole family, ‘je vous embrasse tous de tout mon coeur’. He would not be the only one to find it easier to write to Emma to arrange meetings with her husband than to contact him directly. However, things did not go as planned. We learn from a letter Debussy wrote to Victor Segalen that the rehearsals were ‘lamentable’ leading to Colonne replacing this work with L’après-midi d’un faune on 12 January and asking Debussy to take up the baton himself for La mer on 19 and 26 January. His debut as a conductor at the first rehearsal on Tuesday 14 January was undertaken with a ‘pounding heart’, but the experience was a revelation. He felt he had entered the heart of his own music and turned into an instrument unleashing all its sonorities simply by waving a little stick.

The performance on Sunday 19 January 1908 was also a revelation to the audience. The sharp-tongued critic, Willy (Henry Gauthier-Villars), writing as l’Ouvreuse in Comoedia, commented that the final note unleashed an ovation which proved victoriously the solid construction of the theatre. Never before had he heard such a din as caused by this enthusiasm.

Marriage of Emma and Debussy

The timing of both the rehearsal and the performance must have been particularly stressful for Debussy, for that Sunday 19 January 1908 was the evening before his official marriage to Emma. Whether Debussy believed he was made for domestic life or not, Emma soon had sure grounds to persuade him to confirm their status together, something about which they must have had much discussion in private.