Mad props to Tom Service at The Guardian and the redoubtable Opera Chic for picking up on the Mendelssohn mystery.
A coupla points in response. First of all, Tom S says Mendelssohn was nursing an 'unrequited' passion for Lind. The point is, it was requited, and evidence is said to point to an affair between the two, who went down the Rhine together on a boat, which...but that's a long story. Nevertheless, the affair required squashing, given both their reputations and Mendelssohn's family situation. It wasn't just an unrequited crush, but a genuine lost love.
And even it's true that a composer's music is not directly connected to his/her biography as such, it is necessarily connected to his mind, personality and general state of being, because every note on the page is the product of a personal choice on the composer's part. We've been over this many times here in the blogosphere. The modernist camp especially will deny every jot of it. Everyone would love it not to be the case, musicologically speaking, since that gives us carte blanche to consider only the notes and not the person who wrote them.
I have never been comfortable with that. Would a non-obsessive, stable individual have written Schumann's unbalanced, stream-of-consciousness works with their impossibly repetitive rhythms? Could someone who was not torn apart by the prospect of early and loveless death have written 'Die schone Mullerin' and 'Winterreise' with the devastating power of Schubert? Could someone not prepared to fight for art, humanity and idealism ever have dreamed up Beethoven's Ninth Symphony? Could a non-megalomaniac have written the 'Ring Cycle'? What about Messiaen, religion and birdsong? This could go on and on.
Mendelssohn was more controlled than most, more self-contained and self-effacing, having fewer such battles in his life until the very end; but would someone not thrilled by the atmospheres of Italy and Scotland have written those symphonies? Would someone normally so cheerful and energetic have produced that last, devastating string quartet?
Now, I'm a 'creator' of sorts too and I know from the inside that what and how I choose to write can tell you much more about me than I'd like. For example: I am obsessive. I try to do too much. I consider myself lazy and should wear my glasses more often. I am easily spellbound. I am a dreamer and sometimes ought to get my feet more firmly back to earth. I have a 'thing' about the violin. I am rather an outsider, like to stand back and observe, and slightly enjoy being quietly subversive. I am drawn to difficult and recovering places, histories and people, and yes, this is indeed because I have experienced difficult times that still require recovery, which has been much aided by music, art, writing etc. There is not one directly autobiographical sentence in any of my novels, nor a single character who is based entirely on a real person; yet everything from the story structure to the specific word is there because I chose it, for better or worse, and each is, I imagine, the sum total of a lifetime-so-far's experience and what I've learned to date about human nature.
I have no reason to imagine that a composer would function especially differently. With the one proviso that, as Tom S quotes, in Mendelssohn's words, "It's not that music is too imprecise for words, but too precise."
Perhaps this helps or perhaps it doesn't, but that's my 2 1/2p for what it's worth.