One
Everything makes a difference.
Everything. File that away.
Two
There are two kinds of good sound: good sound sound and good music sound. While I could describe the distinction in few words or many, it's easier to point to two recordings of Elgar's oratorio The Dream of Gerontius: by Sir Adrian Boult and the New Philharmonia Orchestra, with tenor Nicolai Gedda singing the title role (2 LPs, EMI SLS 987); and by Malcolm Sargent and the Liverpool Philharmonic Orchestra, with Heddle Nash in the lead (2 LPs, EMI RLS 709).