I was having problems with my bass guitars, fender JB and P bass and an epiphone viola. After several trips to my local music store, the instruments were checked and I was told they were in tune. They all checked out on the electronic tuning meter. However when playing along with cd's, the instruments still didn't sound right. After a good part of the day experienting, I changed the reference pitch to 445hz. They all sound perfect, no problems with intonation. Why are the guitars in tune at 445hz and not at 440hz?
Post-production often raises the pitch (and increases the tempo) of a recording. Plus, there is no guarantee that the recording was made at A440 in the first place. Further, even in classical music, pitch standards vary regionally. So, it is not surprising that you would find yourself to be out of tune with a recording when you are playing at A440.
If A445 works well with the recordings you are using, go for it.
Consider the source of your recordings, and the process of recording them.
Maybe, after recording the backing track, the producer decided the whole thing benefited from a slight change of tempo. Changing the playback speed affected the tuning.
Maybe, for the session, the band didn't tune to a reference pitch; they just tuned to each other. I remember in some of the obituaries for Dimebag Darrell of Pantera, it was noted that he didn't use a tuner, or unison tuning; he'd turn the tuners until it sounded right to him. I'm sure plenty of musicians do the same.
Maybe the arrangement includes an instrument that can't be tuned, and which is sharp or flat compared to reference pitch.
Maybe the song contains a sample that itself isn't at standard pitch, or has been sped up or slowed down until it's at a non-standard pitch.
Maybe the basis of the song was played on an instrument with continuous pitch control (fretless bass, upright bass, violin, trombone, washtub bass, voice, etc.), and the rest of the arrangement was pitched to match.
The speed of a recording may have varied in the mastering process, either by accident (on old recordings, the speed of tapes and disk cutting platters might not be well controlled), or on purpose (Jake Riviera of Stiff Records notoriously attended mastering sessions and demanded that singles be sped up, so much so that producers began to send him slowed-down versions to compensate).
So you see, there are many, many reasons why a recording might not be tuned to a A440 standard.
Practical solutions, for playing along:
- As you have done, tune your instrument to match the recording
- Adjust the pitch of the recording in software, for example Audacity. Audacity has an option to adjust the pitch independent of tempo (with some quality degradation).
There's always a chance that your CD player is not playing at the 'correct speed'.Unusual, but not impossible. It used to happen frequently with cassette and tape players.If a piece was recorded on a machine that ran slightly slow, then played back on a good one, the recording appeared fast and slightly high, neither of which may have been picked up by just listening.Often I would have to retune a guitar to play along, as the recording sounded like it was 'in the cracks'.