I've probably done it in a joking manner with close friends/family members for the laughs and it does work since your brain processes speech differently when you sing it. At my office, we do a lot of customer service which means a lot of talking and repetition and there's a certain rhythm to how a lot of co-workers speak which I've also adopted. Like a lot of downward and upward inflection. Not sure if it's helped me speak better though.