Music educators strive diligently to develop musically literate student musicians. Sight-reading new music is one way of displaying music literacy because musicians must simultaneously synthesize an understanding of music notation and technical performance skills. Teaching students to sight-read is important towards developing an independent ability to play music for and with others. Providing students with a strong rhythmic foundation significantly enhances sight-reading skills. Rhythmic dictation, a tool for rhythmic development, encourages students not only to recognize rhythms as they hear them but also to reproduce them in written form. This activity may increase rhythm recognition and music performance at first sight (Earney, 2008; Granberry-Gordon, 1994; Jarrell, 1999). This quasi-experimental study examined the effects of two different rhythm units (one with and one without rhythmic dictation) on the sight-reading proficiency of high school wind instrumentalists. Band students at two demographically similar high schools in central Georgia experienced two researcher-designed treatments, an instructional unit of rhythm study with an emphasis upon rhythmic dictation (RD) and a rhythm study unit without dictation (RO). The symphonic and concert bands at both schools experienced one of the two rhythm studies. Only one group per school engaged in daily rhythmic dictation during the course of the study. The other bands at each school received rhythmic instruction without rhythmic dictation assignments. This study used a pretest/posttest design with the "Watkins-Farnum Performance Scale" (Watkins-Farnum, 1954) to determine the effectiveness of the independent variable (rhythm studies) as observed by gain score means. Data analysis procedures included descriptive statistics, a paired-sample t--test, a factorial analysis of variance (ANOVA), as well as a step-wise linear multiple regression to examine any significant effects among the variables. Results of the paired-samples t-test indicated that both groups made statistically significant improvement between pretest and posttest administrations of the WFPS (t[subscript 114] = 4.92, p < 0.001). While both treatment groups had statistically significant improvement from pre- to post-test, the results of the ANOVA indicated that neither treatment (RD or RO) was significantly more effective than the other (F = 0.379, sig. 0.540, p > 0.05). Regression results revealed only one statistically significant, but very weak (R[superscript 2] of 0.037) predictor of sight-reading: piano lessons. The results of this study did not find a statistically significant difference between students who received rhythm study with or without rhythmic dictation. However, this research supports the practical implications for high school band directors who provide in-depth rhythm study for their students. Teaching rhythm concepts in a manner consistent with this study and the supporting literature could help to develop literate student musicians who may ultimately be more successful and proficient performers. Future research should include a comparison group without focused rhythmic instruction. [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.]