Seamless pitch shift

I’m trying something interesting: I created a bass line with distinct notes using a square wave, and currently I’m looking for a way to make a smooth transition between two bass notes. I tried that with sliding time scale to no avail, since I cannot seem to remove the click between the transition. Are there any ways to achieve this? Many thanks.

Probably easier to just generate it as one sound. For example, try running this in the Nyquist Prompt effect (http://manual.audacityteam.org/man/nyquist_prompt.html):

;type generate
(mult 0.8
  (osc-pulse (pwlv 110 0.5 110 1.5  220 2.5 220) 0))