CREATE TABLE "standard" (
  "string" text,
  "scientific_pitch" text,
  "helmholtz_pitch" text,
  "interval_from_middle_c" text,
  "frequency_hz" real
);

Question: What is the lowest Frequency where the Hemholtz pitch is d?
SQL: SELECT MIN("frequency_hz") FROM "standard" WHERE "helmholtz_pitch"='d';

Question: What is the scientific pitch when the Helmholtz pitch is D?
SQL: SELECT "scientific_pitch" FROM "standard" WHERE "helmholtz_pitch"='d';