For example take the Pluck It Section of the Orchestra. you can download all three instruments together or the Banjo, Mandolin and Guitar separately. Then get the samples from the Philharmonia Orchestra, mp3 to wave them and drop the appropriate waves in the samples folder for each instrument.
DIY Violin - 1000 sample instrument with five to six velocity layers in 1/4 second, 1/2 second, 1 second and 1 1/2 second notes as well as pizzicato. Also glissando, legato, martelle, spiccato, staccato, tremolo, trill, detache, punta, talon, and tenuto phrases.
DIY Viola - 800 samples with five velocity layers in 1/4 second, 1/2 second, 1 second and 1 1/2 second notes as well as pizzicato. Also phrases but fewer and more lightly sampled.
DIY Cello Test - A small start.
DIY Philharmonic Pluck It Section - containing Banjo, Mandolin and Guitar
DIY Philharmonic Banjo
DIY Philharmonic Mandolin
DIY Philharmonic Guitar
DIY Brass Section
DIY French Horn
So far the brass instruments contain the 2 Second Instrument (the longest brass samples from Philharmonia last about 2 seconds), Instrument Old (these seem to be older, slightly low quality samples) and Instrument Phrases (trills, crescendos and such). Eventually I'll add in the shorter samples as separate instruments and all in one instrument control by the mod wheel.
The Philharmonia Orchestra have licensed their samples under a Creative Commons Attribution-ShareAlike 3.0 Unported License. You can use these samples for a Commercial Work. Just give attribution to the Philharmonia Orchestra.
Public Domain Picture from Wikimedia.