Is it permitted to listen to recorded music during Sfira? (I understand that there are differing opinions on this subject; my interest is how rabbis of the "nationalist" camp hold.) Thanks!

Listening to recorded music is not permitted for 33 days - each according to his custom. One may listen to songs sung without instruments. At a Se'udat mitzvah music is permitted if the Se'udah is a Simcha Shel Mitzvah.