I am a new whistle player, and was wondering what others do when they are playing a song that has a note lower than the lowest note that the whistle plays? I usually skip the song if there are lots of notes lower than D (I play a D whistle), but there are some songs where there are only a few notes that are one step below the D (just a couple of low C’s).
Thanks in advance for your help.
This is a very frequently asked question. Browse back through the earlier pages and you’ll probably find several threads discussing it.
Here’s one: http://chiffboard.mati.ca/viewtopic.php?topic=1602&forum=1.
Steve is right, go back and read up, this board (Archives) is like a text book on many subjects. It’s worth spending the time to go over what has been said.
Quickly though, if the key of the song fits your D but has notes lower then the bell, then I would play it on my A whistle.
The archives will tell you more young grasshopper. As If I’m a master, yeah right!! 
My apologies for re-asking a question. I read the FAQ and a few screens worth of posts, but did not have the time to read all 32,000+ existing messages.
A short answer is that you can play the same note but an octave higher than it is written. Some tunes will work this way, but not all. Otherwise, it may be possible to play a note which is up a third, or fifth, from the one written, and play harmony. What works will depend on what chord fits into the tune. Finally, it may be that the music is in a key which is not best for the whistle, and can be improved by transposing it into one that will work better.
Playing alone, I often move a tune up or down a fifth, which isn’t so hard if you read music relatively, but I think would be hard if you only know the tune by fingering (fingering to fingering in the head transposition sounds a little dizzying…) Up a fifth adds a sharp, and down subtracts one; up move D to A and down moves D to G.
This method has a major drawback of not allowing you to play with other musicians unless you switch whistles…
Otherwise, up an octave, play the D instead of the the below-D, play a harmonizing note to the below-D note, etc, as people said above.
(Oh, and taking the fingerings from transposing up a fifth and then playing on the A whistle should give you what the poster above meant by ‘playing it on the A whistle’ … conversely, so would learning the A whistle fingers by note name and reading the music directly, but I kinda treat non-D whistles as transposing instruments…)
You could, of course, also some serious money and get a keyed whistle if you really have to have that C. Or build your own. I might do that one day. Or I might just learn to half hole and to love my C whistle…
–ChrisA, adding to the chaos.