After Matisyahu, Roger Steffens is probably the world's most famous white Bob Marley expert from Brooklyn. Gearing up for an extensive tour of Israel beginning Thursday, Steffens' multimedia Bob Marley lectures are so comprehensive that Marley's mother Cedella once thanked Steffens for teaching her so many new things about her son. Steffens began collecting artifacts over 30 years ago for what he calls "Roger Steffens' Reggae Archives." Today, the archives fill six rooms in his home and contain the world's largest collection of Bob Marley video, memorabilia, interviews and live concert recordings. Despite many tempting offers from collectors, Steffens and the Jamaican government have begun planning a museum that will some day house the collection in Kingston. Steffens' love of Marley and reggae has reverberated in his life. He is the founder of the authoritative American reggae magazine, The Beat, which he still runs as publisher, editor, writer and photographer. He has written many books on the subject, including The Definitive Discography of Bob Marley, published just last month. Steffens has compiled many of the definitive reggae collections - including The Complete Bob Marley and the Wailers 1967-1972 retrospective boxed set, Peter Tosh's Honorary Citizen boxed set, and two of Tosh's live concert albums. He has also written many essays for the accompanying liner notes, and hosted a plethora of reggae-themed radio and television shows. Steffens worked through most of the Eighties as a major record label executive in charge of reggae promotion. His Life of Bob Marley lecture tours have taken him from the Rock and Roll Hall of Fame in Cleveland - where Steffens was the first lecturer and remains the most frequently invited - to the United States's official archives at the Smithsonian and on to the rest of the world. This week marks his first lectures in Israel. The presentations promise video footage that has never been shown publicly. Steffens' tour here begins Thursday, January 12 at the Tel Aviv Museum at 9 p.m., (03) 607-7020. On Friday, January 13, he appears at the Kibbutz Tze'elim bar at 10 p.m., (052) 866-4399. January 14, Steffens speaks at the Sderot Cinematheque at 8 p.m., (08) 584-9695. On January 15 he'll be at the Eilat Regional Auditorium (opposite Kibbutz Yotvata) at 9 p.m., (052) 395-9338. January 17 he'll be at the Rosh Pina Cinematheque at 8 p.m., (054) 493-0359. Steffen's final appearance of the tour is on January 18 at the Jerusalem Cinematheque at 9 p.m., (02) 565-4333. Tickets cost NIS 35/45.