Eric Lane, a piano teacher at the South Shore Conservatory, spent his school vacation in a land where until 10 years ago playing or listening to music could get you flogged – or worse. Lane was among 27 American teachers who participated in an eight-week residency program at the Afghanistan National Institute of Music’s third annual winter academy. The program offers Afghanis ages 10 to 30 a chance to improve their musical abilities. During three weeks in Kabul, Lane served 23 piano students, 15 saxophone students, a world music ensemble and a classroom of about 60 elementary schoolchildren, many from orphanages. During the program, students and resident faculty members performed together in casual concerts and formal shows for diplomats and corporates. Lane, who lives in Boston, will be teaching at the Jacobs Elementary School in Hull this spring as part of the conservatory’s artist-in-residence program.