Emacs Mouse Scrolling

I hate the default emacs wheel scrolling---each mouse wheel click is too far for me to track context. These settings go in my .emacs file so that the basic scroll is only 5 lines, Shift allows me more precision and the Control key lets me take bigger jumps.

; Mouse Wheel Scrolling
; Scroll up five lines without modifiers
(defun up-slightly () (interactive) (scroll-up 5))
(defun down-slightly () (interactive) (scroll-down 5))
(global-set-key [mouse-4] 'down-slightly)
(global-set-key [mouse-5] 'up-slightly)
; Scroll up five lines with META held
(global-set-key [M-mouse-4] 'down-slightly)
(global-set-key [M-mouse-5] 'up-slightly)
; Scroll up one line with SHIFT held
(defun up-one () (interactive) (scroll-up 1))
(defun down-one () (interactive) (scroll-down 1))
(global-set-key [S-mouse-4] 'down-one)
(global-set-key [S-mouse-5] 'up-one)
; Scroll up one page with CTRL held
(defun up-a-lot () (interactive) (scroll-up))
(defun down-a-lot () (interactive) (scroll-down))
(global-set-key [C-mouse-4] 'down-a-lot)
(global-set-key [C-mouse-5] 'up-a-lot)