What is the status of additional Shabbat hymns (zemirot/piyyutim) added to Shacharit — are they obligatory or optional?

ShabbatPrayerShabbat Prayer

Synopsis

The Rema records the custom to add Shabbat zemirot, noting that if one omitted them one need not repeat, except for 'La-El Asher Shavat.' The Mishnah Berurah clarifies that this rule applies to all additions made on account of Shabbat, including Nishmas. The Biur Halacha adds nuance about when during the service a correction can still be made.

Early Acharonim
Late Acharonim
Lenient
Strict
Lesser cited
Major authority

Discussion

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