פסח
This melody is used for the opening קדיש of the evening service on the first night of Festivals in the London S&P tradition: קדיש - ליל ראשון של חג [JC]
This chant for הלל הגדול [JC] is borrowed for הלל at the end of the סדר from the Shabbat morning service, where it is sung by the choir/congregation as part of the Zemirot (AKA פסוקי דזמרה); same for this segment of נשמת [DJ] (though in the case of נשמת the Hazzan chants the portion aloud himself) and במקהלות [JC].
At the beginning of the סדר, it is customary to chant the parts of the סדר aloud: קדש ורחץ - Morocco [JC]. {The identical melody is often used in Sephardic congregations for כתר, at the opening of the מוסף קדושה.}
The הגדה itself, in the אשכנזי tradition, has a specific way of being chanted:
נוסח ההגדה [BB]
ברכות ק"ש - תתברך צורנו - KAYJ [MF]
ברכות ק"ש - וכולם מקבלים - KAYJ [MF]
Throughout the first day(s) of פסח the חזן may often choose to borrow the melody of אדיר הוא for various parts of the liturgy:
הלל - הודו - ניגון אדיר הוא - KAYJ [MF]
קדיש 1 - ניגון אדיר הוא - KAYJ [MF]
קדיש 2 - ניגון אדיר הוא - KAYJ [MF]
Some segments of הלל as sung on פסח in the London S&P tradition:
הללו את ה כל גוים [JC]
This melody מן המצר [JC] is derived from the S&P Barukh Habba - ברוך הבא [JC] (commonly sung on the first day of Festivals, and at weddings - even among Ashkenazim!), which shares many musical elements with Bendigamos and the Song of the Sea.
On the first day of פסח the Prayer for Dew, a converse to the Prayer for Rain said on שמיני עצרת, is inserted into מוסף.
On each day of פסח the corresponding portion is inserted into מוסף:
קורבן מוסף - יום ראשון (ושני - בחו"ל) [AGo]
קורבן מוסף - חוה"מ [AGo]
On the last day of פסח, the La Despedida [JC] is set to אין כאלהינו [LSC] as a farewell to the Festival.
והוא רחום - מוצאי פסח - KAYJ [MF]