Programming in assembly for DOS - still valuable these days?

[CZghost]

I'm trying out making a tiny program for DOS which plays Happy Birthday song melody via PC speaker and with each chapter displays its text. After 4th chapter it displays greeting and year of build (2015). I am using DOSBox to emulate the PC speaker sound (it plays through normal speakers by square wave, btw). It works as a charm, I just ommited code to stop sound at the end of 4th chapter, so it continued to play loudly the last tone after program terminated This I am gonna to fix by writing entire program from the very start.

My goal is to ask, if someone still sees any pros of programming DOS applications or is it actualy completely dead and I just try out any ancient phosiles? I know there are still companies that use DOS apps in work to save data on server, so they use still Windows XP on their computers (Windows Vista is crappy and Windows 7 does not support DOS apps anymore in fullscreen mode)... But making such tiny programs that play a simple music...

[VolumetricSteve]

Is making a tiny ASM program that plays happy birthday valuable? Not financially, but possibly in terms of educating yourself.
Is learning ASM valuable? Yes. While it's not something you're likely to use daily...monthly..or yearly, it will greatly improve your understanding of how computers work at a low level.

[CZghost]

We learn ASM in our school, however not for DOS, but a kind of microchip (PIC16F84 for sure), which use different instruction set for similar actions. First DOS works with x84 architecture instruction set a lot greater than the PIC's one. I wanted to try out one of ways programmers in DOS times used to, which seems to be successfuly done. The tiny program is ready to go and available to download. However I do not include download link here since the program is in czech and many of people here won't understand lyrics. I made it for friends, I post link of their FB wall when they have birthdays