Postgres table inheritance would work like so:

create table music (
    id serial primary key,
    common1 int not null, 
    common2 boolean not null
);

create table symphony (
    layers int not null,
    at1 text not null
) inherits(music);

create table concerto (
    lead text not null,
    strings integer not null
) inherits(music);

Consider if we have a row in each table.

insert into concerto (common1, common2, lead, strings)
  values (1, true, 'a', 5);
insert into symphony (common1, common2, layers, at1)
  values (2, false, 3, 'b');
insert into music (common1, common2)
  values (3, true);

They are all rows of music.

-- Fetches id, common1, and common2 from all rows.
select *
from music

If you only want to query rows in music specify only music.

-- Fetches id, common1, and common2 from only the one row in music.
select *
from only music

If you want to use symphony columns, you have to query symphony.

-- Fetches id, common1, common2, layers, at1 only from symphony
select *
from symphony

Try it

A more traditional structure would use join tables like so:

create table music (
    id serial primary key,
    common1 int not null, 
    common2 boolean not null
);

create table music_symphony (
    music_id integer references music(id),
    layers int not null,
    at1 text not null
);

create table music_concerto (
    music_id integer references music(id),
    lead text not null,
    strings integer not null
);

insert into music (id, common1, common2)
  values (1, 1, true);
insert into music_concerto(lead, strings)
  values ('a', 5);

insert into music (id, common1, common2)
  values (2, 2, false);
insert into music_symphony (music_id, layers, at1)
  values (2, 3, 'b');
  
insert into music (id, common1, common2)
  values (3, 3, true);

-- Fetch all symphonies
select *
from music m
join music_symphony ms on ms.music_id = m.id

Try it