In solfège, can you pronounce "sol" like "so"?

From the dictionaries, it seems like at least in American English, "sol" (as in "do, re, mi, fa, sol") is always pronounced "sole," but there's a spelling variation "so" is pronounced "so".

• Oxford (or whatever dictionary Google sources): /sōl/
• Merriam-Webster: /sōl/, or less commonly so /sō/
• dictionary.com: /sohl/; also, so

So it seems like if you want to say /soʊ/, you have to spell it like "so"; and if see "sol", you have to say /soʊl/.

This seems strange, though, since I've almost always heard it pronounced like "so", but "sol" is still a pretty common spelling.

For instance, in these two pretty popular songs, it's pronounced "so" (but then again, the lyrics don't write it as "sol"):

• The Sound of Music - Do Re Mi: "sew, a needle pulling thread"
• blackbear - do re mi ft. Gucci Mane: "do, re, mi, fa, so fuckin' done with you, girl"

So are the dictionaries correct and "sol" = /soʊl/ and "so" = /soʊ/, or is pronouncing "sol" as /soʊ/ okay?

(If this isn't broadening the question too much, I'd also like to ask whether "sole" or "so" is the more usual pronunciation.)

In my chorus class, we generally drop the 'L' and pronounce it as 'so'. I honestly don't think it matters which way you say it; as long as your not going to get marked off for it.

In a comment, Robusto wrote:

So' may be viewed as a corruption of sol for the solfège system, and may come about because the next step on the scale is la, so that the /l/ sounds get jammed together into one: sola, and then, pried apart again, become to the ear so la.