after you've launched the app, click on the plus sign (+) just beneath and a little to the left of your name "you are logged in as "DimaSamara" in the upper right corner of the window. then you see all the colorful audiotools; the middle synth on the second row (with the one octave keyboard) is called a bassline (frequently referred to as 'the 303' or 'TB 303' (the Roland hardware it is modelled on)). you can program your own cool bassline patterns and work them with your samples if you feel like it. :)