Talk is at the heart of classroom instruction and, according to the vast research on classroom talk, the teacher that does most of the talking. Thus, an asymmetry of power is created between teachers and students. These asymmetrical relationships are most obvious in urban elementary classrooms where test prep literacy curriculum has become the dominant approach to literacy instruction. In spite of the debate and challenge by scholars the implementation of this reductionist approach to literacy learning has teachers reading from instructional scripts, drilling phonics skills, and using controlled vocabulary texts. Students are reduced to understanding literacy as answering the "right" questions and reading as many words possible within one minute. This ethnographic case study examines how one urban elementary teacher resisted the dominant approaches of reductionist literacy curriculum by engaging her students in rich and varied opportunities to use literacy for genuine purposes in the form of authentic literacy learning. Within this context of authentic literacy practices the students and teacher engaged in dialogic whole-class talk. Dialogic talk shifts the teacher dominated whole-class talk from answering evaluative questions to a jointly constructed conversation. This study demonstrates how concepts of authority emerged from this dialogic whole-class talk. Varying forms of authority were identified and conceptualized as "in" control, "to" control and "for" control through grounded theory and conversational analysis of whole-class talk. It was the participation structures and negotiated rules of the conversational floor that made each form of control distinct. For the members of this urban elementary class, authority became a jointly constructed accomplishment that fluidly and dynamically moved from one form of control to another. This study demonstrates how authentic literacy learning can provide a space for instructional autonomy through whole class talk, particularly for urban students who have been silenced through the use of dominant literacy instructional approaches. As an interactional accomplishment, authority through whole-class talk, gives urban students a voice. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]