WITH
	-- Configuration parameters:
	duration AS (SELECT    16 AS value), -- in seconds
	bpm      AS (SELECT   120 AS value), -- beats per minute

	-- Numbered beats, the outline:
	beat AS (
		WITH RECURSIVE beat0 AS (
			SELECT 0 AS value
			UNION ALL
			SELECT beat0.value + 1 FROM beat0, duration, bpm
			WHERE beat0.value < (duration.value * bpm.value / 60 - 1)
		)
		SELECT * FROM beat0
	),

	-- Set instruments for particular channels:
	raw AS (
		SELECT 0 AS time, 'c0 0e' AS raw UNION ALL   -- channel 1 = Tubular Bells
		SELECT 0 AS time, 'c1 58' AS raw             -- channel 2 = Fantasia
	),

	-- Parts (quite random sounds):

	drums_1 AS (
		SELECT
			9 AS channel,
			beat.value AS beat, NULL AS custom_time,
			250 * 1000 AS duration,
			CASE WHEN beat.value % 4 IN (0,1,2) THEN 35 ELSE 40 END AS note_pitch,
			80 AS note_velocity
		FROM beat, bpm
	),

	bells_1 AS (
		SELECT
			0 AS channel,
			beat.value AS beat, NULL AS custom_time,
			500 * 1000 AS duration,
			CASE WHEN beat.value / 4 % 2 = 0 THEN 68 ELSE 55 END AS note_pitch,
			90 AS note_velocity
		FROM beat, bpm
		WHERE beat.value % 4 IN (1)
	),

	fantasia_1 AS (
		SELECT
			1 AS channel,
			beat.value AS beat, NULL AS custom_time,
			500 * 1000 AS duration,
			60 + beat.value % 4 AS note_pitch,
			90 AS note_velocity
		FROM beat, bpm
		WHERE beat.value % 4 IN (2,3,0)
	),

	-- Put all parts together:
	notes AS (
		SELECT
			part.*,
			CASE
				WHEN custom_time IS NULL THEN beat * 1000 * 1000 * 60 / bpm.value
				ELSE CAST(custom_time AS integer)
			END AS time
		FROM (
			SELECT * FROM drums_1        UNION ALL
			SELECT * FROM bells_1        UNION ALL
			SELECT * FROM fantasia_1
		) AS part, bpm
	)

-- We need to emit two MIDI events: one for key press and one for key release.
-- So we add the release events (note_on = false) derived from the time and duration values.
SELECT 'note'  AS event, time,                  channel, 1 AS note_on,      note_pitch,      note_velocity, '' AS raw FROM notes   UNION ALL
SELECT 'note'  AS event, time+duration AS time, channel, 0 AS note_on,      note_pitch,      note_velocity, '' AS raw FROM notes   UNION ALL
SELECT 'sysex' AS event, time,             0 AS channel, 0 AS note_on, 0 AS note_pitch, 0 AS note_velocity,       raw FROM raw
ORDER BY time ASC, event DESC;