Which phrases in Shirat HaYam are read with the special 'shirah' trop? (Inspired by this question.)
Based in my Mesora - which I got from my father:
The special tune starts before the Shira. It is already used for Posuk 14:29 - the Posuk before וַיּוֹשַׁע
Note: this phrases is already mentioned in Pasuk 22 - but there it is sung normally.
Then comes the actual Shira, where each Posuk with Hashem's name gets sung with the special Shira trop.
That's true until 3 Psukim before the end:
But we're not done yet - Miriam's Shira is also sung with the Shira trop - i.e. the end of Passuk 21: