Thank you for your feedback. As for "Leonid and Friends" - to me it sounds authentically American :-) I've heard that it's almost impossible to become a popular artist in USA if there is any presence of a foreign accent in singing. Except for a Spain accent, it's considered to be colorful.

I'm not sure about the strings in the song above. In such as arrangement, I guess, samples of a high quality can be safely used without giving out that it's not an actual ensemble is playing.