The last couple of weeks I've been working on and off learning how to create a MIDI backup band for my harmonica. I discovered that there are quite a few .kar files on th internet. These are MIDI files with lyrics that are usually used for singing karaoke. You can turn the lead instrument off and sing along with the band. I downloaded a few tunes including this one.
I'm using Logic Express on my old MacBook as my audio editor and mixing board. I first converted the .kar file to a standard MIDI file using QuickTime 7 Pro. I then imported the MIDI file into Logic. Each instrument comes in as a separate track. I didn't like the sound of the general MIDI piano. So, I changed to the piano sound from my Kruzweil PC88 keyboard. To do this I output the MIDI to my keyboard, plugged the audio outs of the keyboard into the MacBook and recorded the piano as an audio track.
After a lot of research, I figured out how to change the audio inputs for Logic from the Macbook's built-in input to a USB mic so I could then record my harmonica. It was NOT easy or intuitive. Logic does not see a USB mic when it's plugged into the Mac. You can see it in System Preferences, but you can't in Logic. You have to first use the Audio/MIDI Configuration tool in Utilites to create a new device call it USB Mic, assign the input to the USB mic and output to the speakers.Then in Audio Preferences in Logic you can choose the new device.
I also learned how to apply reverb, compression, and other effects to a track in Logic. There are multiple ways to do this. The best way is to use the Send feature to send the output of the track to an auxiliary channel and set the effects in that channel.
The MIDI file I found was in the key of F. My harmonica is a C harmonica. I had to figure out how to transpose the MIDI tracks to the key of C. You would think that you could do this globally with one click, but no, you have to set it for each track.
Finally I figured out how to change the tempo. I wanted to record the harmonica at a reduced tempo and play it back uptempo. You can do this by checking the Follow Tempo check box in the parameters of the track. Logic does a pretty good job of altering the tempo of an audio track as long as you don't try to do too much. I recorded at 40 bpm and upped it to 60.
I practiced and recorded the song using headphones and played along with the other instruments. It's hard. I'm not used to playing with other instruments and sticking to a set tempo. Hopefully I'll get better with practice.
You can use Logic's Bounce feature to output the mix and normalize it. I then used iTunes to change the AIFF file to MP3.