The Flam Drag is probably generally considered a modern rudiment, but actually appears in early 18th century French music.
Swiss Style performed:
American Style performed:
The Flam Drag in Swiss / Basel Music:
In the Basel style, Flam Drags are a variation on the Swiss Army Triplet. They are played as a Right-Hand Flam, Right-Hand Doubles, and Left-Hand Stroke. This sticking creates a Right-Hand Flam followed by a Left-Hand Drag.
The Flam Drag in American Music:
In the American 40 PAS rudiments, Flam Drags are performed alternating, similar to Single Drags. The Americans likely adopted this rudiment from the Swiss / Basel movement and adapted the sticking.
As of yet, there is no indication of this rudiment in earlier American music.
The Flam Drag in French Music:
Some of Philidor’s rudiments can be difficult to interpret without sticking information. However, in one of Philidor’s drum beatings (La Marche des Grenadiers), there is a rhythmic notation that appears to indicate a Flam and a Drag.
The most logical assumption is that it indicates a Flam Drag, much like performed today. Based on the French tendency to utilize the Swiss Army Triplet as a stylistic habit, the sticking is most likely the same as the Swiss Flam Drag.
Later, L’Appel from the 1754 ordonnance demonstrates a variation of a this rudiment performed almost like a Double Drag. (To learn more, see my discussion of ‘Performing French Duty Calls’.)
More Info:
If you have any additional information on the origin or development of this rudiment, please contact me and share your resources. Or, comment below!