The original Grand Concert size guitar, the 12-fret 00 was invented by C. F. Martin in the 1850s and continues to show up in the Martin line every so often, because its full yet balanced tone is beloved by fingerstyle players, while being versatile enough for the main acoustic guitar duties on iconic albums by Bob Dylan and the Rolling Stones. In modern times an S is added to the model name of most 12-fret Martins, so you can tell them apart from the 14-fret versions.
