Big media coverage for a Mendelssohn song, 
The Heart of Man is Like a Mine, written in 1842. Because it was a private commission it was never published and remained in private hands. It's now being auctioned at Christie's  where it might fetch £15,000 - £25,000. Yet manuscripts like these aren't exactly rare. Imagine the media hysteria if some unknown work by Mozart or Schubert 
were found? When dodgy bits of "evidence" or  trivia about a 
composer come up, the world goes agog with frenzy.   But a few years ago a trove of  46 
"unknown" songs by Mendelssohn were unearthed, there was hardly a ripple in the press because the songs were found in  the Bodleian Library in Oxford,  donated via his grandchildren, (of whom there were 
many). Some documents are more significant than others but some get money grabbing headlines. 
  
Mendelssohn 
was so prolific that he simply didn't get around to cataloguing and 
publishing all he wrote. He was a workaholic, a genius in many fields. 
Apart from composing, he was a virtuoso pianist and violinist, a 
painter, an athlete, and a formidable organizer of orchestras and 
cultural events. He spent his gap year in the Scottish Highlands, in 
those days very remote and primitive. He died aged only 38, weakened by 
exhaustion. The "unknown" songs were scattered among his 
manuscripts, which have since themselves been scattered around the 
world.  There's a big cache of Mendelssohn papers in the Bodleian 
Library in Oxford,   so that's where Eugene Asti, the pianist and music historian,  went to follow the trail of the 
"missing" songs.
Mendelssohn's penmanship was so clear that the 
manuscripts were easy to transcribe, even though the composer wrote 
quickly, with great fluency.  Tracking down the poems was in most cases 
straightforward - Goethe, Holty, Uhland - but others proved more elusive
 since some were written by the composer himself, and in Fraktur, the 
old-style German script that most people can't read today.  
Mendelssohn's letters and papers provide background into how and when 
the songs were written, and for whom.  Intriguingly, there are 
references to yet more unknown songs.
What's even more remarkable is how good some of these songs are. 
Nachtlied,
 from 1847, should take its place in any anthology of Eichendorff 
settings. Two lovely matching strophes blossom into swelling, soaring 
lines as the song describes a nightingale, greeting the dawn.
Altdeutsches Frühlingslied,
 also from the same period towards the end of Mendelssohn's life, is 
another masterpiece. The piano part is brooding, melancholy, figures 
repeating like circles, reflecting the despair that lies under the 
ostensibly cheerful text (Friedrich Spee von Langenfeld 1591-1635). 
Spring has returned after a hard winter, "everyone is happy, wallowing 
almost in pleasure" (wonderful idiomatic translation by Richard Stokes).
 But the protagonist quietly states 
Nur ich allein, Ich liede Pein. In
 the winter just past, someone very dear him was taken away.  So much 
nonsense is written about Mendelssohn being "happy" and mindless. This 
song is further evidence how silly the myth is.  Mendelssohn wasn't 
given to unseemly display, he didn't flaff about. But his emotions ran 
very deep indeed. The deeply felt intensity of the final verse breaks 
through the polite homilies to Spring, chilling the 
atmosphere.  Mendelssohn's beloved sister Fanny had just passed away, 
but feelings as passionate as these spring from veryt deep sources in 
the composer's personality.

Part of the reason Mendelssohn songs 
don't grab the average listener at first is that they don't word paint 
the way we're used to. Goethe is famously supposed to have rejected 
Schubert's settings of his poems. There's no direct evidence he even saw
 them, but it fits in with ideas prevalent in Goethe's circles which  
considered noble ideas and text more important than musical invention.  
Mendelssohn was very much in Goethe's orbit. Goethe adored the young Mendelssohn, 
introducing him to composers he knew, like Zelter. So Mendelssohn is 
very much a part of that neo-classical sensibility, where people didn't 
do unseemly self-display.  Nonetheless, Mendelssohn was far too original
 not to connect to the early Romantic mode. He just did it in a 
different, more self-effacing way.  Mendelssohn songs are an important 
thread in song development: at times you can hear where Schumann and 
Brahms got their ideas from.
The Goethean mindset certainly doesn't preclude passion.  
Die Liebende schreibt,
 an 1830 setting of Goethe, is surprisingly erotic. The poet's so much 
in love that his whole being focuses on the idea of a letter from the 
beloved.   Yet in his quietly observant way, Mendelssohn has picked up 
that the beloved does not actually respond.  The composer puts his 
emphasis on the small phrase "Gib mir ein Zeichen", (give me a sign).  
The word 
Zeichen repeats,
 ever louder and more passionately, as if Mendelssohn is reminding us 
that it's been sent out in hope, and there might, conceivably, be no 
answer.
Lots of other beautiful songs, too, like 
Seltsam, Muter, geht es mir (1830
 to Johannes Ludwig Casper). The young girl's thrilled by the physical 
sensation of being in love, like the rising of sap in spring.  
Mendelsson expresses her excitement with breathless, rollicking lines: 
you can almost feel the girl's heart beat faster and faster.  The 
punchline's hilarious, the girl doesn't know why her mother knows about 
such things. This, incidentally, is a song discovered only in 2007 when 
the manuscript came up for sale, having been uncatalogued and in private
 hands for 150 years.  Asti's work is informed by his experience as a pianist, 
so his new edition of the "unknown" songs for Bärenreiter are specially 
valuable for practical performance. It's
 very detailed, lots of notes on critical decisions made and background 
material which will enrich interpretation.  Serious Mendelssohn singers 
and painists need this work.
 HERE is a link to the edition on Bärenreiter's site.
The 
Oxford Lieder Festival brings treasures like this all the time, which is why it's such an 
important series for serious music people. Oxford Lieder was crucial in bringing the "lost" songs to public attention, hosting recitals of "premieres", where singers were accompanied by Eugene Asti himself. Some of these songs  
were written for private performance, like 
Lied zum Geburtstage meines guten Vaters,
 which the 10-year-old Felix wrote for his father's birthday in 1819. 
His sister Fanny wrote a song too, it must have been quite some party.
Mendelssohn
 wrote many part songs because they suit performances where people sing 
and play for pleasure, not to display technique. In his understated way,
 Mendelssohn gets to the heart of why music is so much fun for ordinary 
people.  The final song in this concert was Volkslied, a song where the 
whole ensemble could join together.  Written in 1839, it was performed 
at the composer's funeral service a few years later.  Different soloists
 sing different lines, but they unite in the full-throated final verse, 
 
Wenn Menschen auseinander gehn, so sagen sie : Auf Wiedersehen !
  The last two words repeat again and again as if the composer can't 
bear to let them end. Yet the same notes appear throughout the song, in 
different guises, so if you hear the song again, it's haunted by "Auf 
Wiedersehen".