MIDI editor
 

I just need a very simple program that can increase the volume of midi file. I uploaded a certain midi file I like onto my cellphone, but the volume is way too low.

Also, is there a simple program that will let me delete some parts?

I guess anything that's free would work.

Hang any MIDI editor, 'cos all them has such features. I dunno any freeware, but maybe you can get one old-ware (voyetra midi studio, cake walk 3, or so). Otherwise, try with some shareware, after all, you can always re-install and continue using it.

There's an awesome freeware MIDI editor I've been using for years, Anvil Studio

http://www.anvilstudio.com

It's simple, can get the job done with volume increases, and it also has a really simple interface in case you ever want to start sequencing your own MIDIs.