Alhadeffhar hatt gjesteopptredener på blant annet Tulsa Ballet, Southern Arizona Symphony Orchestra, Karlove Vary Sinfonie, San Luis Obispo Symphony, UCLA Opera Program, South Florida Opera Company, Eastern Sierra Symphony, Bourgas State Opera, Rio Hondo Symphony, Long Beach Opera, Chinese Cultural Center of San Francisco, California State University Los Angeles Opera Teater, California Polytechnic State University Opera Theater Workshop, og Grand Valley State University (MI) Opera, Ballett og Musikkteater.