The connections between music and language are still to be clarified in educational terms; despite the great deal of literature on the common mechanisms underlying their working in learning, memory, and some other related factors, there is not robust research on their combined potential. Educational bilingualism and musical instruction have been shown to facilitate reading in a foreign language. Our study intends to throw light on their potential for reading in a second language and the relationship they keep to self-efficacy, a key factor in such a complex realm as learning a foreign language. The silent reading of 252 Spanish secondary school students was examined to show if bilingual instruction, music training, and self-efficacy influenced second language silent reading fluency (L2 SRF). Our ANOVA analysis shows bilingual instruction having the strongest influence of the three groups analysed, followed by the music training and the standard group. Self-efficacy was also included in the MANOVA model as a covariate and was shown to have an influence on L2 SRF. The study also revealed a significant influence of bilingual and musical instruction on self-efficacy, which may partially account for their effect on L2 SRF.