Wheelbuilding / Wheel Building / Wheel build help

If the wheel is new it's quite normal to get some pinging from the spokes.
During the final stages of the truing and tensioning some of the spokes may have twisted around a bit when the nipple was turned. The ping comes when the spoke twist back in a stres-release cycle.
Don't tension everything, just check trueness when pinging is about stopped.

My front wheel is making a tinkling sound when I'm out of the saddle. Does this mean my spokes are loosing tension? The wheels itself is still true.

Would a few half turns to all the spokes sort this out or is it going to be more effort than that?

The pinging means that somehow the spokes are being plucked. On a newly built wheel that can come from the release of spoke twist, as others have said. Other causes are spokes with too low tension going slack for part of the cycle, or stick-slip motion where spokes weave around one another.

If tension is low, increasing it might help.

Over time spokes fret grooves into one another where they touch at crossing points. As the crossing points move under high loads, the spokes jump in and out of the groove rather than moving smoothly. My worst case of this was when i replaced a rim but used the same spokes in the same places - the old fretted grooves where in almost but not quite the right place in the new build so the spokes were constantly pinging for a while.

You could try cleaning and maybe even greasing the crossovers.