"Though his full name was "Franz Joseph Haydn", the name "Franz" was not used in the composer's lifetime, and the use of "Franz" when referencing him is avoided by scholars." (https://musicbrainz.org/artist/c130b0fb-5dce-449d-9f40-1437f889f7fe)
@Ohr16. First, a great majority of classical recordings, for their title, only list the composer's last name so it would mostly just be "Haydn". Second, it's "Franz Joseph Haydn" not "Franz Josef Haydn"....not even Last.fm spells it this way. Perhaps you should check your own spelling before criticizing others. Third, I have DG recordings where it is spelled as "Franz Joseph Haydn" while others just say "Joseph Haydn". Which spelling you think is correct is a matter of preference, neither of them is wrong per se. If you don't like it, disable auto correct and scrobble it as "Joseph Haydn".....and please NOT "Jozef Haydn", like you seem to suggest,...that for sure IS wrong.
He never reminds me of Vivaldi... for me he is closer to Beethoven than to the earlier composers. That might be because his music is firmly Classical, with many new forms and ideas, in a way unrecognisable from the Baroque era music. I think he has an architectural thought in his music which is unprecedented, and it inspired the genius of Beethoven no end.
I think Haydn is undervalued for these reasons: 1) he has an unique sense of humor which is suspect among a lot of very serious classical music listeners 2) he wrote so much music that it is hard to take him all in.
I would start with the 'Farewell" no.45, the most well known and still my favourite haydn symphony. Any of the 'sturm und drang" symphonies:
Symphony No. 49 in F minor La Passione (1768)
Symphony No. 44 in E minor Trauer (Mourning) (1772)
Symphony No. 45 in F sharp minor Farewell (1772)
Symphony No. 26 in D minor Lamentatione
And the london symphonies, his last twelve
The symphonies are good but a bit overrated, it's all about the Creation and the string quartets for me. The 'Representation of Chaos' in the Creation is fantastic, as are the tone poem portrayals of the creation of eagles, whales, etc.
«В этом мире так мало радостных и довольных людей», — писал семидесятилетний композитор, — «везде их преследуют горе и заботы; быть может, твой труд послужит подчас источником, из которого полный забот и обремененный делами человек будет черпать минутами свое спокойствие и отдых».