We
propose one solution to the problem which consists of widening the
neck as shown in Fig. 4.5, so that semitone blades, hooks, or levers
can be fixed.
Paraguayan
harpists will perhaps object to this modification on the grounds that
their harps are traditional and should therefore remain as they are.
Basically,
there are four types of semitone systems: the hooks, the blades, and
the levers.
- that's as it stands in the book, I don't know what happened
to the fourth one
All
have their merits and drawbacks. The reader will decide which type
to select according to available materials, tools and skill, from
the simple hook of old to the elaborate Japanese lever system.
| 
fig
5.1 - click for a larger view |

Lever
and blade arrangement on Celtic Harp
|

Tuning blades
|

Goulven type tuning
lever
|
-
click for a larger view - |