The Sibelius Group today announced the Mac OS X release of Sibelius 2, the company’s powerful music notation software. Sibelius 2 has been redesigned from the ground up to take advantage of Mac OS X and boasts more than 200 new features, including Arrange, a revolutionary artificial intelligence technology that can automatically arrange and orchestrate music. Sibelius 2 sells for US$599 with upgrades priced at $199. Educational discounts are available.