To find sheet music for a song in the United States, there are several reliable sources. The most popular and accessible platforms include Sheet Music Plus, Musicnotes, and J.W. Pepper. Sheet Music Plus offers a vast collection of sheet music for all instruments and genres, with a user-friendly interface and fast shipping options. Musicnotes provides digital sheet music that can be downloaded instantly, making it convenient for those who prefer digital formats. J.W. Pepper is another well-known retailer that offers a wide range of sheet music, including hard copies and digital downloads.

The popularity of these platforms can be attributed to their extensive catalogs, competitive pricing, and user-friendly interfaces. According to a report by Grand View Research, the global sheet music market size was valued at USD 2.6 billion in 2020 and is expected to grow at a CAGR of 4.5% from 2021 to 2028. This growth is driven by the increasing demand for sheet music among musicians, educators, and hobbyists. The availability of online platforms has significantly contributed to this growth, as they offer convenience, accessibility, and a wide variety of options.