Is there a way to raise/lower ALSA's volume without using a graphical tool? I am currently using MPD along with MPC mapped to hotkeys to change the volume, but I recently switched music players and I would rather not have MPD lying around just to manage the volume (in addition, mpd doesn't work well with esound which I am also using).
NOTE: I am not using a desktop environment like GNOME so DE-specific solutions are not applicable in my case.
You can use alsamixer, a soundcard mixer for ALSA soundcard driver, with an ncurses interface. There's also aumix which is a non-ASLA specific mixer.
If they aren't on your machine, install their packages of the same name.
$sudo apt-get install alsa-utils aumix
Edit: The above is assuming you're on an Ubuntu or Debian system. If you're not, you should find and install the packages using your distribution's package management system.
In the highly unlikely event that these aren't packaged for your system, download them from source here and here and compile.
Another option for non-gui management of alsa is amixer - it provides the same controls as alsamixer, but from the command line instead of via ncurses. amixer with no arguments lists the available controls for the first card (card 0), -c selects the card number. Amixer is especially useful for dumping the state of all the cards settings, and then reloading them later. It is also the best choice for any shell script that wants to modify volume levels.
Check out System -> Preferences -> Keyboard Shortcuts.
There is a section named "Sound" which lets you set shortcuts for system volume.
