Converting music or analog audio recordings on tape to digital formats requires using a computer program to record and convert the audio. Some free and inexpensive programs use your computer's built-in microphone or auxiliary inputs. Simply connect an audio cable from the auxiliary output of a tape deck to the audio inputs on your computer. More expensive programs designed for professional use, such as Apple Logic and ProTools, require an additional interface device called an A/D-D/A converter. These devices have analog audio inputs and convert the signals to digital data. Either a firewire or USB cable then connects the converter to the computer.
Quite a number of free programs for computer recording are available for download on the Internet. Names include Audacity, Kristal, FreeCorder, The GarageDoor, Quartz Audio Mixes, Anvil Studio, and others. These are adequate for converting tape to digital formats for use in MP3 players and to be burned onto CDs that can be played on any CD player. Professional programs, which of course, cost money, have many additional features, such as enhanced editing and customizing audio tools. A sampling of popular professional recording software programs are ProTools, Apple Logic, Cubase, Nuendo, MOTU Digital Performer and Ableton Live.
Once the recording software converts the analog media to a digital format such as WAV or AIFF files, your computer's CD burning program can be used to make music CDs. Or, you can use the software to convert the audio to MP3 files, and connect your MP3 player to your computer to download them.