The most famous piece in Gagaku is "Etenraku." It is often heard during New Year's celebrations.
It is said to be the origin of the "Kuroda Bushi," with various lyrics set to the melody of Gagaku's Etenraku, known as Etenraku Imayo.
You can find a YouTube video here that features a complete set of instruments and is easy to understand.
There is also a VR video of "Etenraku" performed by Reigakusha.
In Bugaku (court dance), "Ryo-o (Ranryo-o)" is famous. Since it is a piece of Tang music, it is a dance of the left side, and as you can see, it features red costumes.
You can watch it on YouTube here.
Another famous piece in Bugaku is "Nasori."
In the left-side Bugaku dances, "Seigaiha" is well-known.
If you search for "Gagaku" on YouTube, you will find various performances. While performances by the Imperial Household Agency and the National Theater are not posted, there are videos of performances by various Gagaku groups.
The Japan Arts Council's Cultural Digital Library has a page on Gagaku.
https://www2.ntj.jac.go.jp/dglib/contents/learn/edc22/index.html
This is a digest, but it includes explanations, making it easy to understand. It also features other genres of traditional Japanese music, so I hope you will get to know the wide range of Japanese traditional music.
The Imperial Household Agency's Music Department has released DVDs.
These come with explanations, making them very easy to understand.
Gagaku
Link to Amazon
Court Music of the Imperial Household
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As for CDs:
Selected Gagaku by the Imperial Household Agency's Music Department
Link to Amazon
Celebratory Gagaku Banzairaku, Etenraku by Reigakusha
Link to Amazon
Gagaku Taikei by Gagaku Shigenkai (CD reissue of the 1962 recording, which won the Minister of Education Award at the 1961 Arts Festival)
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A CD with explanations by Hideki Togi. This is also recommended if you want to enjoy the sound of the hichiriki, as it features classical performances.
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For CDs by Mayumi Miyata, a leading figure in sho performance:
"It includes all the 'Tones' revived from ancient scores over 15 years, and the complete forgotten masterpiece 'Nyusho,' recorded from 800 years ago."
Link to Amazon
Although there is little information and few opportunities to experience Gagaku performances, you can enjoy them through videos, DVDs, and CDs.
It might be nice to immerse yourself in the sounds of ancient times.
