Picture credits

The pictures used on this website are licensed under Creative Commons. They can be found at the following locations: 

Flute

https://commons.wikimedia.org/wiki/File:Flûte_traversière_2.png

Clarinet 

https://commons.wikimedia.org/wiki/File:Yamaha_Clarinet_YCL-457II-22_(rotated).jpg

Alto saxophone

https://commons.wikimedia.org/wiki/File:Etude_Alto_Saxophone.JPG

French Horn

https://commons.wikimedia.org/wiki/File:French_horn_back.png

Trumpet

https://commons.wikimedia.org/wiki/File:Trumpet,_B_flat_-1623.jpg

Trombone

https://commons.wikimedia.org/wiki/File:Yamaha_Trombone_comparison_of_open_and_traditional_wrap.jpg

Tuba

https://en.wikipedia.org/wiki/Tuba#/media/File:Yamaha_Bass_tuba_YFB-822.tif

Violin

https://commons.wikimedia.org/wiki/File:Violin_front.jpg

Cello

https://nl.wikipedia.org/wiki/Cello#/media/Bestand:Cello_front_side.png

Choir

https://upload.wikimedia.org/wikipedia/commons/a/ae/FHM-Choir-mk2006-02.jpg

Tokyo string quartet

https://www.flickr.com/photos/92269745@N00/4999895776

King’s College Cambridge

https://commons.wikimedia.org/wiki/File:King%27s_College,_Cambridge,_in_the_snow_1.jpg

King College Cambridge

My thanks to the original posters.