This is an old song that sounds lovely on the Piano-Accordion. 
(beginners can simplify Bdim/G to G and Am7 to Am). 
I suggest reading the history behind this song, because it adds a new depth to 
the understanding of the beauty of this piece. AMouse197.

http://en.wikipedia.org/wiki/The_Bonnie_Banks_o%27_Loch_Lomond
http://www.youtube.com/watch?v=Qu_aBryealw - this is a video of this tab being played

G (320003@1)         Bdim/G           C (x32010@1)         DBy (xx0232@1)yon bonnie banks and by yon bonnie braes,
           G (320003@1)         Em (022000@1)         C (x32010@1) DWhere (xx0232@1)the sun shines bright on Loch Lo-mon'.
      C (x32010@1)      G (320003@1)              Am7 (x02010@1)        Cwhere (x32010@1)me and me true love were ever wont to gae
        G (320003@1)            C (x32010@1)          D (xx0232@1)GOn (320003@1)the bonnie, bonnie banks o' Loch Lo-mon'.

Chorus:
   G (320003@1)           Bdim/G             C (x32010@1)           DO (xx0232@1)ye'll tak' the high road and I'll tak the low road,
     G (320003@1)         Em (022000@1)    C (x32010@1)   DAn' (xx0232@1)I'll be in Scotland afore ye;
    C (x32010@1)        G (320003@1)            Am7 (x02010@1) Am (x02210@1)  CBut (x32010@1)me and me true love will never meet again
        G (320003@1)            C (x32010@1)          D (xx0232@1)GOn (320003@1)the bonnie, bonnie banks o' Loch Lo-mon'.

G (320003@1)          Bdim/G         C (x32010@1)     D'Twas (xx0232@1)there that we parted in yon shady glen,
        G (320003@1)         Em (022000@1)         C (x32010@1) DOn (xx0232@1)the steep, steep sides o' Ben Lo-mon',
          C (x32010@1)        G (320003@1)        Am7 (x02010@1) Am (x02210@1)     CWhere (x32010@1)in deep purple hue the Hieland hills we view,
         G (320003@1)         C (x32010@1)        D (xx0232@1)  GAn' (320003@1)the moon comin' out in the gloa-min'.

(chorus)
     G (320003@1)         Bdim/G            C (x32010@1)           DThe (xx0232@1)wee birdies sing and the wild flow'rs spring,
        G (320003@1)         Em (022000@1)         C (x32010@1) DAnd (xx0232@1)in sunshine the waters lie slee-pin';
          C (x32010@1)            G (320003@1)        Am7 (x02010@1) Am (x02210@1)  CBut (x32010@1)the broken heart it ken nae second spring again,
         G (320003@1)         C (x32010@1)             D (xx0232@1)  GTho' (320003@1)the waefu' may cease frae their gree-tin'