HI HELLO i am here to offer a little more detail on the genre for week 2, "classical/orchestral", which is kind of unclear/unfocused as it stands.
"classical" in the broad, modern sense usually means anything written for the concert stage and for acoustic instruments (and usually specifically the Western, often Euro-centric canonical works of instruments found in orchestras, wind ensembles or choirs - a lot of the stuff Max linked is among the most famous to those who haven't really been exposed further). the term "classical" is somewhat confusing though because in the history of this tradition, there is also a "Classical" (capital C) period, defined by dudes like Mozart, Haydn and Beethoven and specifically referring to a timeframe of about 1730-1820. people in this sphere tend to say "art music" instead of "classical music" as the broader term if they are very pretentious, but imo "concert music" is most sensible. "orchestral" on the other hand is more of a descriptor than a genre, dictating the colors you're painting with so to speak. it's like "chiptune" in that regard, it tells you the sorts of sounds you expect to hear. (incidentally, i firmly disagree about jazz, which can indeed be incorporated in this music. Gershwin's "Rhapsody in Blue" is probably the most famous example of this and that dates all the way back to the 1920s! however, it's probably safe to assume one of the other weeks of Hum 2 will be jazz fusion, so maybe it is not relevant to discuss that this week...)
anyway, although the Classical period has some structural relevance to VGM (especially with its heavy focus on melody + accompaniment - that guy Mozart sure knew how to spin those), i think it is most relevant to talk about the Romantic period (which came right after Classical) and about Impressionism which followed thereafter. the Romantics were by and large the first composers to really embrace emotion for its own sake, and broad fascination with nature, mysticism etc... what this meant for music was that it became more about self-expression with clearer associations of what the music "meant", and generally sought to break free of the rigid forms and harmony of earlier periods (probably the thing you think of as "Music Theory(TM)"). by and large, VGM composers subscribe to a similar ethos, which is to say their music is infused with emotion and is allowed to deviate harmonically without following strict rules about what "can" and "cannot" be done (like how parallel fifths weren't allowed in Bach's time).
another thing that i think is essential when discussing VGM and concert music is that the Romantics were the first to start writing "programmatic" (or just "program") music; that is, music written to represent something specific. (often this info would be given in the program notes of concerts) these guys were the original guys writing "Level Music"! that concept wasn't always around in the concert music tradition, but i think it's especially important to mention since nearly all VGM is written to underscore something specific, be it a type of area or a cutscene or a particular battle. (one of my college professors actually liked to call old Nintendo music "Japanese Neo-Romanticism") this trend continues with the Impressionists, btw, who focused strongly on atmosphere and color in music and often titled their pieces evocatively after particular "pictures" of sorts (examples below).
a little more on Impressionism - these guys basically totally stopped caring about "functional" harmony at all (i.e. common leadings of one chord to another within a key, and proper resolution of dissonances into consonances) and used lots of extended chords, often in parallel. which is to say, these guys were the original guys writing "transposecore". sounds were chosen for their color above all else. this tradition is also evident in the works of many video game music composers, and the two most notable Impressionists - Debussy and Ravel - are no doubt BIG influences on the VGM pedigree. (Koji Kondo has gone on the record saying that originally, the Zelda theme was just Ravel's Bolero, but ultimately had to write something different because of copyright)
oh! one more thing, Wagner (who started out as a Romantic guy and kinda grew more modern over his life's work) was a pioneer in the use of the "leitmotif", a melodic fragment used to represent a certain character. in his case this was for huge, sprawling operas, but you probably know this technique from "mr. tony fox undertale" using it in his popular game "undertale". it is a common technique, and due to the storytelling nature of many video games, is relevant history to the medium.
one last thing before i start dumping links - if you feel intimidated trying to approach this genre, you probably intuitively understand more about it than you think you do. yes, there is a lot of tradition and theory behind a lot of this stuff, but the most relevant part of it to writing VGM is not actually that part, and if you are steeped in video game music you surely have it in your blood to write something approaching this style. broadly speaking i'd recommend focusing on a melody and paying close attention to how you accompany it, particularly with other moving lines (this is "counterpoint" or "what keffie does in her music"); rework it and develop it as your song goes, rather than looping a single phrase, and introduce new textures freely. generally speaking this is one of the most fundamental differences from electronic music; though there can absolutely be structure to your song, you are not really "grooving". (rules are made to be broken of course, and Ravel does this with Bolero, but i have to speak generally here) harmonically you can really do whatever; like i mentioned before, Impressionists were basically transposecore, writing lots of harmonies and melodies in parallel intervals, and Romantics were less strict about Classical era harmony, so write how you feel in this regard.
Debussy - Prelude to the afternoon of a faun
Debussy - The Sunken Cathedral
Ravel - Une Barque sur l'Ocean
Debussy - La Mer
Stravinsky - The Rite of Spring
Chopin - Nocturne Op.27 No.2
Ravel - Bolero
Mussorgsky - Pictures at an Exhibition
Ravel - Pavane for a dead princess
Milhaud - Suite Francaise
Brahms - 6 Piano Pieces, Op.118
Strauss (Richard) - Don Juan
HERE ALSO are some links provided by hanna from various time periods baroque through impressionist:
bach passion according to matthew (bach rules. michiru yamane knows this)
menuet from french suite 3 (as heard in russian block game)
couperin - les mysterieuses barricades (harpsichord. instrument number 7 in general midi. )
actually classical period
haydn sonata 60
mozart symphony 40
beethoven sixth symphony
beethoven string quartet op. 135
faure - fantasie