NY Times Crossword
August 23, 2020
Barbara Lin (adapted)
(Title shown below)

Each clue below has two parts. The answer to the second part is the same as the answer to the first part with the addition of two or three letters - according to a certain pattern. What are the two answers to each clue and what is the pattern that distinguishes them from each other? The first set of answers is limited to the first part of each clue. The second set gives the second answer (with the additional letters) and reveals the pattern.

[Note from JA: Personal opinion - brilliant puzzle]

1. It's often played on bagpipes - Iditarod, for one
2. One temporarily raising a child not one's own -
    One driving kids around in a Subaru model
3. Give a kidney to save someone's life, for example
    Letting out all the stops to drown out other instruments
4. Like fossil fuels and rain forests
    Cocaine and guns in a Pacino movie
5. Unofficial, but organized army-like fighters
    Troops who are worried about sun protection
6. Grandma's  mom
    Give mom's mom the stink eye
7. Hamlin hero
    Eleventh of the "Twelve Days of Christmas" performers
    who invites sympathy

Answers to the first part of each clue:

1. AMAZING GRACE
2. FOSTER PARENT
3. ORGAN DONATION
4. SCARCE RESOURCES
5. PARAMILITARY
6. GREAT GRANDMA 
7. PIED PIPER

Answers to the second part of each clue:

1. AMAZING GRACE - AMAZING DOG RACE 
2. FOSTER PARENT - FORESTER PARENT 
3. ORGAN DONATION - ORGAN DOMINATION
4. SCARCE RESOURCES - SCARFACE RESOURCES 
5. PARAMILITARY - PARASOL MILITARY 
6. GREAT GRANDMA  - GLARE AT GRANDMA
7. PIED PIPER - PITIED PIPER

Pattern: The notes of the musical scale are inserted into the first answers to get the second ones - leading to the puzzle title: MUSICAL INTERLUDE.