select song from track
where album = 

(select album from track
group by album
having count(song) = 

(select max(counts) from
(select count(song) as counts from track
group by album) subsel))



select song from track
where album =

(select album from track
group by album
having count(song) >= all
(select count(song) from track
group by album))


in postgres only:

select song from track
where album =

(select album from
(select album, count(song) from track
group by album
order by count(song) desc) subsel
LIMIT 1)