U.S.A. based Jerry Freeman has built a commendable worldwide name for his considerable creativity and technical know how when it comes to enhancing the voice and playability of a whistle.
We all love and enjoy playing on many different standard whistle models. However, a great deal of eminent whistlers fully endorse that once a whistle has been "tweaked" by Jerry, it becomes a much better instrument - cleaner and easier playing, without buzzes, rattles and squawks, and with the full richness of the sound brought out.
We have been stocking Jerry's Tweaks since we started out and we can honestly say there are not many people who can surpass Jerry's outstanding and in depth grasp of the science of the whistle.
This general guide to Jerry's whistles may be of use:
The Blackbirds (Eb, D and C; black top, nickel tube) are the purest/sweetest voiced. They take the lightest breath. Some like the fact you can play a longer passage without taking a breath.
The Bluebirds (Eb, D; blue top, nickel tube, "Bluebird" label) are at the pure/sweet end of the continuum, but a little more complex than the Blackbirds. They retain some of the distinctive Generation character, but they're sweeter than Generations.
The tweaked Generations are voiced to match as closely as possible, the vintage, pre-1980's Generations, which were a bit sweeter than the Generations being made now, but still a bit more complex/reedy than the Blackbirds and Bluebirds.
The Mellow Dog (green top, brass tube) is a wide body whistle. It has a bigger sound, and takes more of a “push” of air, especially at the top end. (This refers to the key of D Mellow Dog. A C Mellow Dog is a standard body C whistle, exactly the same as a key of C Blackbird except for the brass tube and green color of the top.)