We used FLAMES+GIRAFFE ( Medusa mode ) at the VLT to obtain moderately high resolution spectra for 30 red horizontal branch ( RHB ) stars , 4 RR Lyrae variables , and 17 blue horizontal branch ( BHB ) stars in the low-concentration , moderately metal-rich globular cluster NGCÂ 6723 ( [ Fe/H ] = -1.22 \pm 0.08 Â from our present sample ) . The spectra were optimized to derive O and Na abundances . In addition , we obtained abundances for other elements , including N , Fe , Mg , Ca , Ni , and Ba . We used these data to discuss the evidence of a connection between the distribution of stars along the horizontal branch ( HB ) and the multiple populations that are typically present in globular clusters . We found that all RHB and most ( 13 out of 17 ) BHB stars are O-rich , Na-poor , and N-poor ; these stars probably belong to the first stellar generation in this cluster . Only the four warmest observed stars are ( moderately ) O-poor , Na-rich , and N-rich , and they probably belong to the second generation . While our sample is not fully representative of the whole HB population in NGCÂ 6723 , our data suggest that in this cluster only HB stars warmer than \sim 9000 Â K , that is one fourth of the total , belong to the second generation , if at all . Since in many other clusters this fraction is about two thirds , we conclude that the fraction of first/second generation in globular clusters may be strongly variable . In addition , the wide range in colour of chemically homogeneous first-generation HB stars requires a considerable spread in mass loss ( > 0.10 Â M _ { \odot } ) . The reason for this spread is yet to be understood . Finally , we found a high Ba abundance , with a statistically significant radial abundance gradient .