Hi Harpisti,
Here is another little practice exercise that allows you to not only work on your bending skills and accuracy, but it also shows us a sort of interesting little riff that makes use of chromaticism. It will work on any key Richter harp and the tabs look like this (play it with a swing feel):
-4-4' +4-3/// Z
-3-3' -3"-2/// z (-1)-2"/ -2'-2/
Playing notes: the -3/// and -2/// mean that you hold the -3 and the -2 for a while (you can do a “hand-wa” while holding them, if you want to do that). The (-1) means that this starts “off beat” – that is, it starts on the “and” when you count your beats like this: “one and two and three and … (etc)” while the following -2"/ is played on the “one” beat and is held for that beat. A big Z means to pause for one beat. A small z means to pause for a half-beat.
Begin this slowly (use a metronome – like this online one – at, for example, 60 bpm or whatever you can do without error. Gradually increase speed as you master each speed level.
If you do this exercise regularly, you will find that your bending at the lower end will improve and become more “automatic” (your “muscle memory”) and also more accurate (temporally and tonally). You can use your tongue to articulate the notes or you can use “glottal closure” to achieve a similar effect.
Let me know how this works for you.
Regards,
– Slim 
I hope that it is not too disappointing … I have included an additional bar of “chromaticism” at the end of the video (but it is only as tabs – I did not record it).
,
