This Collings MF O has an Adirondack spruce top with an oval sound hole, a building technique that gives the mandolin a warm, mellow tone. Most of you are probably more familiar with mandolins with f-holes, which tend to have a much brighter, crisper tone and a little more volume. (Think of Bill Monroe's powerful tone and just about every bluegrass band ever.) The sweeter tone of the MF O is perhaps a little light for bluegrass, but it sounds great for jazz, old-time string band music, Celtic music and playing fiddle tunes. As with all of the instruments Collings makes, the craftsmanship on this MF O is meticulous. At first glance, this looks like a fairly plain instrument but the closer you get, the more you can see the detail and care that have earned Collings the reputation for crafting some of the finest mandolins being made today.