Sibelius started to write his diary on a long-term basis in London, at the end of February 1909. He had taken a large notebook with him and on the first page written down bills due for payment, so that he could keep an eye on his finances during his journey.

However, the notebook did not become merely a tool for keeping financial records, even if Sibelius did continue to record financial matters in it. He evolved a system of underlining financial matters in red and the dates of completion of compositions in green.
Apart from recording his finances, Sibelius needed the diary as a substitute for a “friend”. He had survived a throat operation less than a year earlier and for the time being given up cigars and alcohol. “Do not lapse into tobacco and alcohol. Instead, scribble in your ‘diary’. Confide your bad humour to ‘paper’,” Sibelius wrote.

For whom did Sibelius write his diary? “Only I and Aino – and possibly one other person – are allowed to read this diary,” Sibelius wrote. Did he mean some family member or possibly the writer of his future biography?

In the estate of Sibelius two large thick notebooks were found. The composer had filled up the first of these by the end of 1913. There are a few loose pages from the spring of 1914. In August 1914 Sibelius started a new notebook. He wrote in it regularly until the 1920s. Towards the end of the decade the notes become less frequent and then stop altogether. One of the last important processes described in the diary is the composer’s struggle to control his alcohol consumption during the summer of 1927. The struggle ended in triumph, and the composer lived to be nearly 92 years old.

There are very few notes from the years 1928-1935. In August 1943 Sibelius returned to his diary for a few months and clarified his negative attitude towards National Socialism. There are two notes from January 1944, followed by a shopping list. The diary of the 80-year-old composer ends with an undated expression of opinion which is difficult to interpret.

Professor Fabian Dahlström has carried out a complete content analysis of both diaries. It shows that in his diaries Sibelius used the following languages:

Sibelius names 34 uncompleted works, and the diaries contain two different lists of compositions that await revision. There are eighteen works in one of these lists and eight in the other. The diaries contain very little musical notation. In fact, there are only six themes in all, including “the call of the cuckoo”.

In his diary Sibelius writes down weather reports, finances, natural phenomena, the names of people he has met and discussions he has had. He reports everyday incidents, his journeys and family gatherings. The diaries also reveal the composer’s times of gloom. Negative criticism depressed him, as did the temporary – and often well-founded – periods when his wife would not speak to him. To his family he sometimes said that he would go and get rid of his bad moods in his diary, and once he called his diary his “spittoon”. In fact, the diary tends to portray Sibelius as a more melancholy person than he actually was.

Erik Tawaststjerna, who wrote a five-volume biography of Sibelius, entered into the intellectual world of his subject in an unparalleled way. He identified within the diaries the many roles which the composer assumed at the moment of writing.
The rhetorician: “Death! You have to accept your fate. Work for as long as you can. How much time you have thrown away!”
The ironist: “Such a fanatic [I am]!
The observer: “It seems I cannot learn the art of working! That love of the writing desk.”
The satirist: “The tables which I have loved have been covered with tablecloths and decorated with bottles.”
The consoler: “Been working in my own way. Maybe this serves as a means towards an end.”
The composer’s diaries are a real treasure for the researcher. Selections from them have already been published in several books on Sibelius, and researchers can now study them in the National Archive (special permission required). We still await the publication of the complete diaries as a critical edition.