Salvadoran team members looked confused when what was supposed to their anthem blared from loudspeakers at FedEx Field on Saturday night. Several slowly dropped their hands from their chests. Many of the Salvadorans in the crowd whistled in disgust.
CMS Sports expressed regret over the "unfortunate incident" and took "full responsibility for this honest mistake." The company did not say which music was played in place of El Salvador's anthem.
"This was not done with malicious intentions," it added, saying it would take steps to prevent this from happening again.
Salvadoran coach Albert Roca made no reference to the anthem mix-up after the match. Messages were not immediately returned from the Salvadoran Embassy in Washington and CONCACAF, the regional soccer body for North and Central America and the Caribbean.