In 1999 Sigur Rós released 'Ágætis Byrjun' ('A Good Start'), which Q magazine deemed 'the last great record of the 20th century'. By the end of the year, it had won the inaugural US Shortlist Prize for Artistic Achievement in Music. This 20th Anniversary edition of the album features demo and archive versions of the songs, plus never-before-heard newly-unearthed material from the time, rare b-sides and the full 95-minute concert played in Reykjavík on the day the record was released.

CD 1: Ágætis Byrjun

1. Intro - 1:36
2. Svefn-g-englar - 10:04
3. Starálfur - 6:47
4. Flugufrelsarinn - 7:47
5. Ný Batterí - 8:11
6. Hjartað Hamast (Bamm Bamm Bamm) - 7:11
7. Viðrar Vel Til Loftárása - 10:18
8. Olsen Olsen - 8:03
9. Ágætis Byrjun - 7:56
10. Avalon - 4:00

CD 2: Live At Íslenska Óperan, 1999

1. Intro - 3:18
2. Von - 9:32
3. Syndir Guðs - 5:30
4. Flugufrelsarinn - 9:07
5. Olsen Olsen - 6:07
6. Agaetis Byrjun - 7:34
7. Viðrar Vel Til Loftarasa - 8:33
8. Svefn-g-englar - 9:28
9. Ny Batteri - 5:59
10. Nyja Lagið - 9:48
11. Hafsol - 15:21

CD 3: Rarities

1. Hugmynd 1 (Demo 1998) - 6:57
2. Hugmynd 2 (Demo 1998) - 4:01
3. Hugmynd 3 (Demo 1998) - 9:49
4. Debata Mandire (Live At Laugardasholl, 1999) - 3:46
5. Rafmagnið Buið (From Ny Batteri EP. 2000) - 5:51

CD 4: Rarities (Alternative Demos And Live Tracks)

1. Svefn-g-englar (Live At Popp I Reykjavik, 1998) - 11:53
2. Staralfur (Original Speed Version) - 6:25
3. Flugufrelsarinn (1998 Demo) - 8:48
4. Ný Batterí (First Mix) - 7:06
5. Hjartað Hamast (Bamm Bamm Bamm) (1995 Demo) - 9:13
6. Viðrar Vel Til Loftarasa (Alternative Ending) - 11:05
7. Olsen Olsen (1998 Demo) - 7:26
8. Ágætis Byrjun (1998 Demo) - 7:57