Wednesday, June 1, 2011

Classical Music on an iPod - 1

A person unfamiliar with computer based audio asked about setting up a simple HiFi system for a family member with a 200 CD collection of classical music. He wanted something that would play music from computer files and be easy to use. I suggested a combination of Audioengine A5 speakers, an Audioengine W2 iPod to speakers wireless transmitter and an iPod to hold the music. The person doing the project liked the idea and I volunteered to provide some tips.

I long since ripped my CD collection to computer files and more recently copied a subset of my music files to an 80 GB iPod. I had used the J. River Media Center software (JRMC) for all but one step and the Foobar2000 software for that step. However, I wanted to recommend a simpler way for a beginner to accomplish the same thing. I looked at using several different pieces of software before deciding that iTunes would be the simplest tool for this job. The job would be complicated enough that I needed to provide some detailed instructions for using iTunes. That is the subject of this post and the following one. Some questions and answers first.

How much space will be required?

A CD can contain over 70 minutes of music. That requires over 700 Mbytes of space. When the CD is ripped to profuce music files, the amount of storage required depends on the format used:

Wav or AIFF format – requires the same 700 Mbytes.

Lossless format like Apple Lossless format (ALAC) – compresses the data in a way that allows it to be exactly reconstructed. The amount of space varies but is usually half to 2/3 the space of the data on the CD. My rule of thumb is 3 CDs to a Gigabyte since some CDs are are shorter than 70+ minutes of audio.

Lossy formats such as MP3 or AAC – These sacrifice exact reconstruction to allow for smaller storage requirements. A good choice for this project might be AAC with 320 Kilobits per second. Our 70+ minute CD would take 175 Mbytes. My rule of thumb might be 5.5-6 CDs per gigabyte.

What format do we pick?

200 CDs might require ~ 50 Gbytes in ALAC format and 25-30 Gigabytes in AAC format.

Your choice. Storing audio in lossless files means that you won't have to repeat the ripping process again (unless you fail to back up your data.) Storing data in lossy files mallows you get get more on an iPod of a specific size.

How to we label the music files so that we can browse and select what we want to play?

We will choose folder and file names that describe the contents of the music files. However, the iPod will rely on tags stored in the files for browsing the collection on the iPod.

The process of transferring music from audio Cds to music files is called ripping CDs by many people and importing CDs in iTunes. The CD doesn't contain a description of what's on the CD so iTunes looks up the descriptive tags in an online tag database. You can edit the tags values before the CD is imported. The tag values will be used to create folder and file names for the music files and will be stored in the music files.

For classical music, we need a tag to describe who composed the music and a different tag to describe the performer(s). Online tag database aren't very good at providing tag information that is consistent in format or spelling. In addition, the form of names is often wrong for use in browsing music files. You have to be prepared to edit the values returned from the online tag database.

Before I specify the content of individual tags, I'll describe how we browse for music on the iPod.

Many classical music lovers have their CDs arranged by Composer and by work for that composer. If we have several performances of a work, we file them by performer for each composer and work. On the iPod, we would select a Composer, then an work (album) and then an individual track (which might identify an particular artist's performance or identify an individual work in a set.)

We might also have some compilations of short works performed by a star soloist. Those CDs would be filed by Performer then by CD album name and then by individual work.. On the iPod, we would select a performer (Artist), type of work or CD album name (Album) and then by individual work (Track name.)

What tags do we want to use and what do we put in those tags?

Tag name - what we want in it

Genre - classical, rock, jazz, etc. This will be useful for random play within a genre.

Composer - last name of the composer (unless we need a first name appended to make it unambiguous)

Album - the name of the work performed in the music file. If the work is a single track and is part of a set of similar works by a composer (such as waltzes by Chopin), we would use waltzes as the Album tag value.

Artist - the performer(s). For an orchestral work, this would be the conductor's name followed by an underscore character and then the orchestra name. When possible, use a last name for the conductor and a shortened orchestra name. For a concerto work with a soloist, we would specify soloist's last name_conductor's last name_orchestra name.

Track name - for small works contained in a single track, we would put the name of the work here followed by an underscore and the Performer's last name. For works that span several tracks on the CD, we will do a trick to compensate for the deficiencies in the iPods features. We would put the composer name_work name_perofmrer last name in the track name tag for such a multi-movement performance.

For works that span more than one track, we are going to combine the tracks so that the while performance is in a single music file. This lets us select a single track name asd an additional browsing and selecting step. It also ensures that when we let the iPod play music at random, it will play entire works rather than single movements of works.

That's what we want to do. The next post describes how we do it.

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