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;