  The JLab 12 GeV upgrade with a proposed solenoid detector and the CLAS12
detector can provide the granularity and three-dimensional kinematic coverage
in longitudinal and transverse momentum, $0.1\le x \le 0.5$, $0.3 \le z \le
0.7$ with $P_T \le 1.5 {\rm GeV}$ to precisely measure the leading twist
chiral-odd and $T$-odd quark distribution and fragmentation functions in SIDIS.
The large $x$ experimental reach of these detectors with a 12 GeV CEBAF at JLab
makes it {\em ideal} to obtain precise data on the {\em valence-dominated}
transversity distribution function and to access the tensor charge.
