Database schema:

CREATE TABLE tags (
	"index" INTEGER -- example: ['0', '1'],
	id INTEGER -- example: ['0', '2'],
	tag TEXT -- example: ['funk', '1970s'],
	PRIMARY KEY ("index"), 
	CONSTRAINT fk_tags_torrents FOREIGN KEY(id) REFERENCES torrents (id)
)


CREATE TABLE torrents (
	"groupName" TEXT -- example: ['spiderap / a corona jam', 'superappin&#39;'],
	"totalSnatched" INTEGER -- example: ['239', '156'],
	artist TEXT -- example: ['grandmaster flash & the furious five', 'ron hunt & ronnie g & the sm crew'],
	"groupYear" INTEGER -- example: ['1979', '1980'],
	"releaseType" TEXT -- example: ['single', 'album'],
	"groupId" INTEGER -- example: ['720949', '728752'],
	id INTEGER -- example: ['0', '1'],
	PRIMARY KEY (id)
)

Question: From 1980 to 2000, which artist had the most disco releases?
Evidence: From 1980 to 2000 refers to groupYear between 1980 and 2000; tag = 'disco'; the most releases refer to MAX(COUNT(id));

SQL:
SELECT T1.artist FROM torrents AS T1 INNER JOIN tags AS T2 ON T1.id = T2.id WHERE T1.groupYear BETWEEN 1980 AND 2000 AND T2.tag LIKE 'disco' GROUP BY T1.artist ORDER BY COUNT(T2.tag) DESC LIMIT 1