Why Aren’t Musical Instruments Allowed
in Orthodox and Conservative Services?

Musical instruments were once integral to Jewish worship but are now generally prohibited in Orthodox and Conservative services on Shabbat and holidays. This prohibition stems from rabbinic interpretations that date back to the Second Temple era.

Music in Biblical Worship

In biblical times, music played a significant role in worship. Miriam, for example, played the tambourine after the crossing of the Red Sea (Exodus 15:20), and instruments like the shofar, harp, and lyre are mentioned frequently in the Psalms (Psalms 150:1–4, 92:1–4). Instruments were also used to mark joyous occasions, with Numbers 10:10 instructing the use of trumpets. In the First and Second Temples, instrumental music was central to daily worship, including Shabbat and holidays (Mishnah, Arakhin 2:3).

The Rabbinic Prohibition on Instruments

However, during the rabbinic period, the use of musical instruments on Shabbat and holidays was prohibited. The Mishnah banned activities like smacking, dancing, and clapping on these days, and the Talmud explained that these actions were forbidden in case they led to repairing a broken instrument—considered work, which is prohibited on Shabbat. Rashi and later authorities, like Rabbi Ovadiah Yosef, extended this prohibition to playing instruments, as it might lead to repairs.

Another reason cited for the ban is the concept of excessive noise. Rabbenu Hananel argued that loud noise contradicts the restful spirit of Shabbat, reasoning extended to musical instruments.

The Chabad movement adds a spiritual dimension, distinguishing between instrumental music (zemer) and vocal music (shir). Rabbi Schneur Zalman of Liadi explained that instrumental music is tied to the body, while the song is tied to the soul. Since Shabbat is dedicated to the soul, vocal music is more appropriate than instrumental music, which is considered more physical.

While post-Talmudic authorities like the Tosafists and Rabbi Menahem Ha-Meiri offered more lenient views, the dominant legal codes, such as the Mishneh Torah and Shulhan Arukh, upheld the ban on instruments on Shabbat and holidays.

Contemporary Practices in Different Movements

Orthodox communities continue to observe this ban, while vocal music remains integral to worship. The issue has been debated in the Conservative Movement. A 1958 responsum by Rabbi Philip Segal allowed organ music on Shabbat, arguing that it enhances worship and classifying it as a “mitzvah accessory.” However, more recent responses have not led to widespread acceptance of instruments.

Reform Judaism, in contrast, embraces the use of instruments on Shabbat and holidays. This practice began in 19th-century German Reform synagogues, where organ music was introduced. This distinguishes Reform from Orthodoxy, which opposed it on both halakhic and cultural grounds.

The Use of Vocal Music

In contrast to the prohibition of instruments, using choirs in worship services is more widely accepted within these traditions. Vocal music, organized in a choir format, allows for a rich communal expression of prayer without violating the halakhic restrictions associated with instrumental music. The human voice considered a purer form of worship, is embraced as a means to enhance the spiritual experience while still adhering to the underlying principles of Jewish law. This distinction highlights the adaptability of Jewish worship practices, allowing for musical expression that aligns with communal values and traditions while respecting historical prohibitions.

Sources: Joshua Rabin, “Instruments on Shabbat and Holidays,” My Jewish Learning. 
Yehuda Shurpin, “Why can’t we connect to G‑d through music on the Shabbat?” Chabad. 
“Contemporary Issues In Halakha: Musical Instruments In Synagogue,” Sefaria.