Sacrum bodies are seen to be united at their circumferences by bone, wide intervals being left centrally, which, in the fresh state, are filled by the intervertebral discs. The dorsal surface of the sacrum is convex and narrower than the pelvic surface. In the middle line is the median sacral crest, surmounted by three or four tubercles—the rudimentary spinous processes of the upper three or four sacral vertebrae. On either side of the median sacral crest is a shallow sacral groove, which gives origin to the multifidus muscle. The floor of the groove is formed by the united laminae of the
Canticum Sacrum Canticum Sacrum Canticum Sacrum ad Honorem Sancti Marci Nominis is a 17-minute choral-orchestral piece composed in 1955 by Igor Stravinsky (1882–1971) in tribute "To the City of Venice, in praise of its Patron Saint, the Blessed Mark, Apostle." The piece is compact and stylistically varied, ranging from established neoclassical modes to experimental new techniques. The second movement, "Surge, Aquilo", represents Stravinsky's first movement based entirely on a tone row. Though most often abbreviated ""Canticum Sacrum"", the piece's full name is "Canticum Sacrum ad honorem Sancti Marci Nominis", or "Canticle to Honor the Name of Saint Mark". Stravinsky selected all of