Question: What magazine is a monthly music magazine devoted to guitarists,  Christian Science Sentinel or Guitar World?
Context: The Christian Science Sentinel (originally the "Christian Science Weekly") is a magazine published by the Christian Science Publishing Society based in Boston, Massachusetts.  The magazine was launched by Mary Baker Eddy in 1898.  It includes articles, editorials, and accounts of healings from a Christian Science point of view. Guitar World is a monthly music magazine devoted to guitarists, published since July 1980.  It contains original interviews, album and gear reviews, and guitar and bass tablature of approximately five songs each month.  The magazine is published 13 times per year (12 monthly issues and a holiday issue).  Formerly owned by Harris Publications, Future US bought the magazine in 2003.  In 2012, NewBay Media bought the Music division of Future US.  The latter company also published a spin-off title, Guitar Legends, each issue of which typically combined past articles from "Guitar World" under a specific theme. The Word was a monthly music magazine published in London.  It was voted UK 'Music Magazine Of The Year' in 2007 and 2008.  It ran for 114 issues, the last bearing the cover date August 2012. A Reader in a Christian Science church is a member of the congregation who has been elected to serve in one of two positions responsible for church services.  Each week's sermon in Christian Science churches is outlined in the "Christian Science Quarterly", prepared months in advance, and is the same in all Christian Science churches, worldwide.  A lay church, it has no clergy; rather, the sermons consist of passages from the "Bible" and the Christian Science textbook, are studied as lessons during the week and are read aloud to the congregation on the Sunday following. The Christian Science Hymnal is a collection of hymns sanctioned for use in Christian Science services including Sunday services and Wednesday evening testimony meetings, as well as in occasional informal hymn sings.  It includes both traditional Christian hymns, traditional hymns with minor adaptations better suiting Christian Science theology, and hymns unique to Christian Science, including seven poems by the denomination's founder Mary Baker Eddy set to various tunes: "Christ, My Refuge", "Christmas Morn", "Communion Hymn", "Feed My Sheep", "Love", "Mother's Evening Prayer", and "Satisfied".  Found in the Supplement section are the hymns, "I Need Thee Every Hour", "I'm a Pilgrim and I'm a Stranger", and "Eternity", which were originally included in the Hymnal in accordance with [Mrs. Eddy's] wish." The Herald of Christian Science was first published in 1903 in response to the demand for a monthly publication on Christian Science in Germany.  Due to an increasing demand for Christian Science Literature from other countries, the "Herald" grew to include twelve different languages.  Until the 90’s the magazine was bilingual, with English and translated texts side by side.  Currently the "Herald" is available in fourteen languages, giving readers around the world an understanding of Christian Science practice.  Along with articles and accounts of healing, each issue includes a directory of Christian Science churches, practitioners and other listings applicable to each language.  "The Herald" is also produced as a radio program in five languages. Top 40 Music Magazine was an English-language South African monthly music magazine published nationwide in print form between 1984 and 2002. Blow Up is an Italian monthly music magazine, focusing primarily on alternative and obscure music.  It specializes in the coverage of house music, electronica, experimental music, industrial music, queercore, techno, and jazz improvisation.  Besides articles related to music, the magaaine also contains sections devoted to literature and film analysis.  The editor of the magazine is Stefano Isidoro Bianchi, who is also the founder.  The section on literature is curated by Fabio Donalisio, and the film section by Roberto Curti. Ear Magazine was a monthly music magazine devoted to new music.  The magazine was in circulation between 1973 and 1991.  It often dealt with musical applications of feminism, politics, and the environment.  It was also notable for its extensive listings of new music events in the Bay Area, and later, New York. A Christian Science practitioner is an individual who prays for others according to the teachings of Christian Science.  Treatment is non-medical, rather it is based on the Bible and the Christian Science textbook, "Science and Health with Key to the Scriptures" (1875) by Mary Baker Eddy (1821–1910), who "discovered" Christian Science in 1866 and founded the Christian Science church in 1879.  According to the church, Christian Science practitioners address physical conditions, as well as relationship or financial difficulties and any other problem or crisis.  Practitioners are either "listed" or "unlisted," a designation that refers to a form of international accreditation maintained by The Mother Church, in Boston, Massachusetts.
Answer: Guitar World