Normalize not centering Western Chord labels in Music Theory. In quintal harmony, it'd be a C2; In a quartal one it's a D5/2; not sus chords at all. Parallel seconds (and ninths) are way common in Eastern Orthodox traditions.
"The notations of znamenny polyphony require a special approach to their transcription; but when correctly read the music of the ‘scores’ abounds in harsh sonorities in the form of extended parallel seconds & fifths.”
Brazhnikov, qtd in Swan "Russian Music & its Sources..." p45
“The voices enter at the interval of the second and, within a short period of time, four more vertical intervals of the second appear in a row. In the process, the voices cross.”
Vladislav Uspensky, quoted in Johann von Gardner's "Russian Church Singing" Vol. 2, pg. 316
"An organ was installed on a Northwest Stratocruiser in the 1950s through an arrangement with local musician Swanee Swanson. The organists received free flights to New York and other East Coast destinations."
Welsh Harp tablature from the *Robert ap Huw manuscript* (1613). The manuscript is the oldest extant source of primarily Late Medieval eisteddfod repertory that dates to 1340-1500 and was compiled by Robert ap Huw (c.1580-1665).
Short segment on the *Robert ap Huw manuscript* in Rhodri McDonagh's wonderful "Welsh Trad Music | A Beginner's Guide" video (cued up to that segment below). The whole vid is worth a watch and is only 24 minutes.
Bangor University's "Music of the Robert ap Huw Manuscript" page with other resources for Cerdd Dant and other British Isles harp traditions.
One of the things I love about Georgian Harmony is that it's based on what's essentially close to a functionally 7TET/EDO collection of pitches. Many global harmonic systems are built on different tuning systems than those in what's typically referred to as Western harmony.
The above image from Malkhaz Erkvanidze's "On Georgian Scale System" pg. 181
Latest update to the <Solo Keyboard Repertoire - Southeast Asian Composers> resource. Added about another 50 or so pieces by (primarily) Vietnamese/Vietnamese diasporan composers.
I think it's easy to underestimate the size and diversity of SE Asia (hence why I added a new second paragraph to the doc). For example, Indonesia alone has a population of nearly 275 million: the 4th most populous country in the World. About 231 million Indonesians are Muslim.
And just hearing all those different composers that've created wonderfully expressive uses of the piano for native tunes, or how they've incorporated that into their compositional style or, in some cases, incorporated the piano into SEA folk and art musics, is just so refreshing!